Digital broadcasting system and method of processing data in digital broadcasting system

ABSTRACT

A digital broadcast system and a method of processing data disclose. A receiving system of the digital broadcast system may include a baseband processor, a management processor, and a presentation processor. The baseband processor receives broadcast signals including mobile service data and main service data. The mobile service data configures a RS frame, and the RS frame includes the mobile service data and at least one type of channel setting information on the mobile service data. The management processor decodes the RS frame to acquire the mobile service data and the at least one type of channel setting information on the mobile service data, then extracts position information of an SDP message. Herein, the SDP message includes Codec information for each component in the respective virtual channel from the channel setting information, thereby accessing the SDP message from the extracted position information and gathers SDP message information. The presentation processor decodes mobile service data of a corresponding component based upon the gathered SDP message information.

This application claims the benefit of U.S. Provisional PatentApplication No. 60/957,714, filed on Aug. 24, 2007, U.S. ProvisionalPatent Application No. 60/974,084, filed on Sep. 21, 2007, U.S.Provisional Patent Application No. 60/977,379, filed on Oct. 4, 2007,U.S. Provisional Patent Application No. 61/044,504 filed on Apr. 13,2008, U.S. Provisional Patent Application No. 61/059,811, filed on Jun.9, 2008, U.S. Provisional Patent Application No. 61/076,686, filed onJun. 29, 2008 and Korean Patent Application No. 10-2008-0082929, filedon Aug. 25, 2008, which are hereby incorporated by reference as if fullyset forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a digital broadcasting system and amethod of processing data in a digital broadcasting system fortransmitting and receiving digital broadcast signals.

2. Discussion of the Related Art

The Vestigial Sideband (VSB) transmission mode, which is adopted as thestandard for digital broadcasting in North America and the Republic ofKorea, is a system using a single carrier method. Therefore, thereceiving performance of the digital broadcast receiving system may bedeteriorated in a poor channel environment. Particularly, sinceresistance to changes in channels and noise is more highly required whenusing portable and/or mobile broadcast receivers, the receivingperformance may be even more deteriorated when transmitting mobileservice data by the VSB transmission mode.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a digitalbroadcasting system and a data processing method that are highlyresistant to channel changes and noise.

Another object of the present invention is to provide a receiving systemand a data processing method that is capable of acquiring sessiondescription protocol (SDP) information, when a session descriptionprotocol (SDP) message for each virtual channel exists, by receivingposition information of the corresponding SDP message via signalinginformation.

A further object of the present invention is to provide a receivingsystem and a data processing method that is capable of receivinginternet protocol (IP) access information and description informationcorresponding to each component for each respective virtual channel viasignaling information.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, areceiving system includes a baseband processor, a management processor,and a presentation processor. The baseband processor receives broadcastsignals including mobile service data and main service data. Herein, themobile service data may configure a Reed-Solomon (RS) frame, and the RSframe may include the mobile service data and at least one type ofchannel setting information on the mobile service data. The managementprocessor decodes the RS frame so as to acquire the mobile service dataand the at least one type of channel setting information on the mobileservice data. The management processor then extracts positioninformation of a session description protocol (SDP) message. Herein, theSDP message includes Codec information for each component in therespective virtual channel from the channel setting information.Accordingly, the management processor accesses the SDP message from theextracted position information and gathers SDP message information. Thepresentation processor decodes mobile service data of a correspondingcomponent based upon the gathered SDP message information.

The baseband processor may further include a known sequence detectordetecting known data sequences included in at least one data group, thedata group configuring the RS frame. Herein, the detected known datasequence may be used for demodulation and channel equalization of themobile service data.

The channel setting information may correspond to a service map table(SMT), and the SDP position information may be included in the SMT in adescriptor format, so as to be received.

When an SDP reference type included in the SDP position informationindicates that the SDP message is being received in a sessionannouncement protocol (SAP) stream format, the management processor mayaccess an SAP stream so as to gather SDP message information from theSDP position information.

Alternatively, when an SDP reference type included in the SDP positioninformation indicates that the SDP message is being received in an SDPfile format through a file delivery over unidirectional transport(FLUTE) session, the management processor may access a FLUTE session soas to gather SDP message information from the SDP position information.

According to another aspect of the present invention, a method forprocessing data in a receiving system includes receiving broadcastsignals including mobile service data and main service data, wherein themobile service data is capable of configuring an RS frame, and whereinthe RS frame includes the mobile service data and at least one type ofchannel setting information on the mobile service data, decoding the RSframe so as to acquire the mobile service data and the at least one typeof channel setting information on the mobile service data, extractingposition information of a session description protocol (SDP) message,the SDP message including Codec information for each component in therespective virtual channel from the channel setting information, therebyaccessing the SDP message from the extracted position information andgathering SDP message information, and decoding mobile service data of acorresponding component based upon the gathered SDP message information.

According to another aspect of the present invention, a receiving systemincludes a baseband processor, a management processor, and apresentation processor. The baseband processor receives broadcastsignals including mobile service data and main service data. Herein, themobile service data may configure a Reed-Solomon (RS) frame, and the RSframe may include the mobile service data and at least one type ofchannel setting information on the mobile service data. The managementprocessor decodes the RS frame so as to acquire the mobile service dataand the at least one type of channel setting information on the mobileservice data. The management processor then extracts Codec informationfor each component in the respective virtual channel from the channelsetting information. The presentation processor decodes mobile servicedata of a corresponding component based upon the gathered SDP messageinformation.

Herein, the channel setting information may correspond to a service maptable (SMT), and the Codec information may be included in the SMT in adescriptor format, so as to be received.

According to a further aspect of the present invention, a method forprocessing data in a digital broadcast receiving system includesreceiving broadcast signals including mobile service data and mainservice data, wherein the mobile service data is capable of configuringan RS frame, and wherein the RS frame includes the mobile service dataand at least one type of channel setting information on the mobileservice data, decoding the RS frame so as to acquire the mobile servicedata and the at least one type of channel setting information on themobile service data, extracting Codec information for each component inthe respective virtual channel from the channel setting information, anddecoding mobile service data of a corresponding component based upon theextracted Codec information.

Additional advantages, objects, and features of the invention may berealized and attained by the structure particularly pointed out in thewritten description as well as the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a block diagram showing a general structure of adigital broadcasting receiving system according to an embodiment of thepresent invention;

FIG. 2 illustrates an exemplary structure of a data group according tothe present invention;

FIG. 3 illustrates an RS frame according to an embodiment of the presentinvention;

FIG. 4 illustrates an example of an MH frame structure for transmittingand receiving mobile service data according to the present invention;

FIG. 5 illustrates an example of a general VSB frame structure;

FIG. 6 illustrates a example of mapping positions of the first 4 slotsof a sub-frame in a spatial area with respect to a VSB frame;

FIG. 7 illustrates a example of mapping positions of the first 4 slotsof a sub-frame in a chronological (or time) area with respect to a VSBframe;

FIG. 8 illustrates an exemplary order of data groups being assigned toone of 5 sub-frames configuring an MH frame according to the presentinvention;

FIG. 9 illustrates an example of a single parade being assigned to an MHframe according to the present invention;

FIG. 10 illustrates an example of 3 parades being assigned to an MHframe according to the present invention;

FIG. 11 illustrates an example of the process of assigning 3 paradesshown in FIG. 10 being expanded to 5 sub-frames within an MH frame;

FIG. 12 illustrates a data transmission structure according to anembodiment of the present invention, wherein signaling data are includedin a data group so as to be transmitted;

FIG. 13 illustrates a hierarchical signaling structure according to anembodiment of the present invention;

FIG. 14 illustrates an exemplary FIC body format according to anembodiment of the present invention;

FIG. 15 illustrates an exemplary bit stream syntax structure withrespect to an FIC segment according to an embodiment of the presentinvention;

FIG. 16 illustrates an exemplary bit stream syntax structure withrespect to a payload of an FIC segment according to the presentinvention, when an FIC type field value is equal to ‘0’;

FIG. 17 illustrates an exemplary bit stream syntax structure of aservice map table according to the present invention;

FIG. 18 illustrates an exemplary bit stream syntax structure of an MHaudio descriptor according to the present invention;

FIG. 19 illustrates an exemplary bit stream syntax structure of an MHRTP payload type descriptor according to the present invention;

FIG. 20 illustrates an exemplary bit stream syntax structure of an MHcurrent event descriptor according to the present invention;

FIG. 21 illustrates an exemplary bit stream syntax structure of an MHnext event descriptor according to the present invention;

FIG. 22 illustrates an exemplary bit stream syntax structure of an MHsystem time descriptor according to the present invention;

FIG. 23 illustrates segmentation and encapsulation processes of aservice map table according to the present invention;

FIG. 24 illustrates a flow chart for accessing a virtual channel usingFIC and SMT according to the present invention;

FIG. 25 illustrates an exemplary MH system architecture according to thepresent invention;

FIG. 26 illustrates a 2-step signaling method using the FIC and SMTaccording to the present invention;

FIG. 27 illustrates an exemplary bit stream syntax structure of aservice map table (SMT) according to another embodiment of the presentinvention;

FIG. 28 illustrates an exemplary bit stream syntax structure of anSDP_Reference_Descriptor( ) according to the present invention;

FIG. 29 illustrates an exemplary bit stream syntax structure of aSession_Description_Descriptor( ) according to the present invention;

FIG. 30 illustrates an exemplary bit stream syntax structure of anAVC_Video_Description_Bytes( ) according to the present invention;

FIG. 31 illustrates an exemplary bit stream syntax structure of aHierarchy_Description_Bytes( ) according to the present invention;

FIG. 32 illustrates an exemplary bit stream syntax structure of anSVC_extension_Description_Bytes( ) according to the present invention;

FIG. 33 illustrates an exemplary bit stream syntax structure of anMPEG4_Audio_Description_Bytes( ) according to the present invention; and

FIG. 34 to FIG. 36 illustrate a flow chart showing a method foraccessing mobile services according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

DEFINITION OF THE TERMS USED IN THE PRESENT INVENTION

In addition, although the terms used in the present invention areselected from generally known and used terms, some of the termsmentioned in the description of the present invention have been selectedby the applicant at his or her discretion, the detailed meanings ofwhich are described in relevant parts of the description herein.Furthermore, it is required that the present invention is understood,not simply by the actual terms used but by the meaning of each termlying within.

Among the terms used in the description of the present invention, mainservice data correspond to data that can be received by a fixedreceiving system and may include audio/video (A/V) data. Morespecifically, the main service data may include A/V data of highdefinition (HD) or standard definition (SD) levels and may also includediverse data types required for data broadcasting. Also, the known datacorrespond to data pre-known in accordance with a pre-arranged agreementbetween the receiving system and the transmitting system.

Additionally, among the terms used in the present invention, “MH”corresponds to the initials of “mobile” and “handheld” and representsthe opposite concept of a fixed-type system. Furthermore, the MH servicedata may include at least one of mobile service data and handheldservice data, and will also be referred to as “mobile service data” forsimplicity. Herein, the mobile service data not only correspond to MHservice data but may also include any type of service data with mobileor portable characteristics. Therefore, the mobile service dataaccording to the present invention are not limited only to the MHservice data.

The above-described mobile service data may correspond to data havinginformation, such as program execution files, stock information, and soon, and may also correspond to A/V data. Most particularly, the mobileservice data may correspond to A/V data having lower resolution andlower data rate as compared to the main service data. For example, if anA/V codec that is used for a conventional main service corresponds to aMPEG-2 codec, a MPEG-4 advanced video coding (AVC) or scalable videocoding (SVC) having better image compression efficiency may be used asthe A/V codec for the mobile service. Furthermore, any type of data maybe transmitted as the mobile service data. For example, transportprotocol expert group (TPEG) data for broadcasting real-timetransportation information may be transmitted as the main service data.

Also, a data service using the mobile service data may include weatherforecast services, traffic information services, stock informationservices, viewer participation quiz programs, real-time polls andsurveys, interactive education broadcast programs, gaming services,services providing information on synopsis, character, background music,and filming sites of soap operas or series, services providinginformation on past match scores and player profiles and achievements,and services providing information on product information and programsclassified by service, medium, time, and theme enabling purchase ordersto be processed. Herein, the present invention is not limited only tothe services mentioned above.

In the present invention, the transmitting system provides backwardcompatibility in the main service data so as to be received by theconventional receiving system. Herein, the main service data and themobile service data are multiplexed to the same physical channel andthen transmitted.

Furthermore, the transmitting system according to the present inventionperforms additional encoding on the mobile service data and inserts thedata already known by the receiving system and transmitting system(e.g., known data), thereby transmitting the processed data.

Therefore, when using the transmitting system according to the presentinvention, the receiving system may receive the mobile service dataduring a mobile state and may also receive the mobile service data withstability despite various distortion and noise occurring within thechannel.

Receiving System

FIG. 1 illustrates a block diagram showing a general structure of areceiving system according to an embodiment of the present invention.The receiving system according to the present invention includes abaseband processor 100, a management processor 200, and a presentationprocessor 300.

The baseband processor 100 includes an operation controller 110, a tuner120, a demodulator 130, an equalizer 140, a known sequence detector (orknown data detector) 150, a block decoder (or mobile handheld blockdecoder) 160, a primary Reed-Solomon (RS) frame decoder 170, a secondaryRS frame decoder 180, and a signaling decoder 190.

The operation controller 110 controls the operation of each blockincluded in the baseband processor 100.

By tuning the receiving system to a specific physical channel frequency,the tuner 120 enables the receiving system to receive main service data,which correspond to broadcast signals for fixed-type broadcast receivingsystems, and mobile service data, which correspond to broadcast signalsfor mobile broadcast receiving systems. At this point, the tunedfrequency of the specific physical channel is down-converted to anintermediate frequency (IF) signal, thereby being outputted to thedemodulator 130 and the known sequence detector 140. The passbanddigital IF signal being outputted from the tuner 120 may only includemain service data, or only include mobile service data, or include bothmain service data and mobile service data.

The demodulator 130 performs self-gain control, carrier recovery, andtiming recovery processes on the passband digital IF signal inputtedfrom the tuner 120, thereby translating the IF signal to a basebandsignal. Then, the demodulator 130 outputs the baseband signal to theequalizer 140 and the known sequence detector 150. The demodulator 130uses the known data symbol sequence inputted from the known sequencedetector 150 during the timing and/or carrier recovery, therebyenhancing the demodulating performance.

The equalizer 140 compensates channel-associated distortion included inthe signal demodulated by the demodulator 130. Then, the equalizer 140outputs the distortion-compensated signal to the block decoder 160. Byusing a known data symbol sequence inputted from the known sequencedetector 150, the equalizer 140 may enhance the equalizing performance.Furthermore, the equalizer 140 may receive feed-back on the decodingresult from the block decoder 160, thereby enhancing the equalizingperformance.

The known sequence detector 150 detects known data place (or position)inserted by the transmitting system from the input/output data (i.e.,data prior to being demodulated or data being processed with partialdemodulation). Then, the known sequence detector 150 outputs thedetected known data position information and known data sequencegenerated from the detected position information to the demodulator 130and the equalizer 140. Additionally, in order to allow the block decoder160 to identify the mobile service data that have been processed withadditional encoding by the transmitting system and the main service datathat have not been processed with any additional encoding, the knownsequence detector 150 outputs such corresponding information to theblock decoder 160.

If the data channel-equalized by the equalizer 140 and inputted to theblock decoder 160 correspond to data processed with both block-encodingand trellis-encoding by the transmitting system (i.e., data within theRS frame, signaling data), the block decoder 160 may performtrellis-decoding and block-decoding as inverse processes of thetransmitting system. On the other hand, if the data channel-equalized bythe equalizer 140 and inputted to the block decoder 160 correspond todata processed only with trellis-encoding and not block-encoding by thetransmitting system (i.e., main service data), the block decoder 160 mayperform only trellis-decoding.

The signaling decoder 190 decoded signaling data that have beenchannel-equalized and inputted from the equalizer 140. It is assumedthat the signaling data inputted to the signaling decoder 190 correspondto data processed with both block-encoding and trellis-encoding by thetransmitting system. Examples of such signaling data may includetransmission parameter channel (TPC) data and fast information channel(FIC) data. Each type of data will be described in more detail in alater process. The FIC data decoded by the signaling decoder 190 areoutputted to the FIC handler 215. And, the TPC data decoded by thesignaling decoder 190 are outputted to the TPC handler 214.

Meanwhile, according to the present invention, the transmitting systemuses RS frames by encoding units. Herein, the RS frame may be dividedinto a primary RS frame and a secondary RS frame. However, according tothe embodiment of the present invention, the primary RS frame and thesecondary RS frame will be divided based upon the level of importance ofthe corresponding data.

The primary RS frame decoder 170 receives the data outputted from theblock decoder 160. At this point, according to the embodiment of thepresent invention, the primary RS frame decoder 170 receives only themobile service data that have been Reed-Solomon (RS)-encoded and/orcyclic redundancy check (CRC)-encoded from the block decoder 160.Herein, the primary RS frame decoder 170 receives only the mobileservice data and not the main service data. The primary RS frame decoder170 performs inverse processes of an RS frame encoder (not shown)included in the transmitting system, thereby correcting errors existingwithin the primary RS frame. More specifically, the primary RS framedecoder 170 forms a primary RS frame by grouping a plurality of datagroups and, then, correct errors in primary RS frame units. In otherwords, the primary RS frame decoder 170 decodes primary RS frames, whichare being transmitted for actual broadcast services.

Additionally, the secondary RS frame decoder 180 receives the dataoutputted from the block decoder 160. At this point, according to theembodiment of the present invention, the secondary RS frame decoder 180receives only the mobile service data that have been RS-encoded and/orCRC-encoded from the block decoder 160. Herein, the secondary RS framedecoder 180 receives only the mobile service data and not the mainservice data. The secondary RS frame decoder 180 performs inverseprocesses of an RS frame encoder (not shown) included in thetransmitting system, thereby correcting errors existing within thesecondary RS frame. More specifically, the secondary RS frame decoder180 forms a secondary RS frame by grouping a plurality of data groupsand, then, correct errors in secondary RS frame units. In other words,the secondary RS frame decoder 180 decodes secondary RS frames, whichare being transmitted for mobile audio service data, mobile videoservice data, guide data, and so on.

Meanwhile, the management processor 200 according to an embodiment ofthe present invention includes an MH physical adaptation processor 210,an IP network stack 220, a streaming handler 230, a system information(SI) handler 240, a file handler 250, a multi-purpose internet mainextensions (MIME) type handler 260, and an electronic service guide(ESG) handler 270, and an ESG decoder 280, and a storage unit 290.

The MH physical adaptation processor 210 includes a primary RS framehandler 211, a secondary RS frame handler 212, an MH transport packet(TP) handler 213, a TPC handler 214, an FIC handler 215, and a physicaladaptation control signal handler 216.

The TPC handler 214 receives and processes baseband information requiredby modules corresponding to the MH physical adaptation processor 210.The baseband information is inputted in the form of TPC data. Herein,the TPC handler 214 uses this information to process the FIC data, whichhave been sent from the baseband processor 100.

The TPC data are transmitted from the transmitting system to thereceiving system via a predetermined region of a data group. The TPCdata may include at least one of an MH ensemble ID, an MH sub-framenumber, a total number of MH groups (TNoG), an RS frame continuitycounter, a column size of RS frame (N), and an FIC version number.

Herein, the MH ensemble ID indicates an identification number of each MHensemble carried in the corresponding channel.

The MH sub-frame number signifies a number identifying the MH sub-framenumber in an MH frame, wherein each MH group associated with thecorresponding MH ensemble is transmitted.

The TNoG represents the total number of MH groups including all of theMH groups belonging to all MH parades included in an MH sub-frame.

The RS frame continuity counter indicates a number that serves as acontinuity counter of the RS frames carrying the corresponding MHensemble. Herein, the value of the RS frame continuity counter shall beincremented by 1 modulo 16 for each successive RS frame.

N represents the column size of an RS frame belonging to thecorresponding MH ensemble. Herein, the value of N determines the size ofeach MH TP.

Finally, the FIC version number signifies the version number of an FICcarried on the corresponding physical channel.

As described above, diverse TPC data are inputted to the TPC handler 214via the signaling decoder 190 shown in FIG. 1. Then, the received TPCdata are processed by the TPC handler 214. The received TPC data mayalso be used by the FIC handler 215 in order to process the FIC data.

The FIC handler 215 processes the FIC data by associating the FIC datareceived from the baseband processor 100 with the TPC data.

The physical adaptation control signal handler 216 collects FIC datareceived through the FIC handler 215 and SI data received through RSframes. Then, the physical adaptation control signal handler 216 usesthe collected FIC data and SI data to configure and process IP datagramsand access information of mobile broadcast services. Thereafter, thephysical adaptation control signal handler 216 stores the processed IPdatagrams and access information to the storage unit 290.

The primary RS frame handler 211 identifies primary RS frames receivedfrom the primary RS frame decoder 170 of the baseband processor 100 foreach row unit, so as to configure an MH TP. Thereafter, the primary RSframe handler 211 outputs the configured MH TP to the MH TP handler 213.

The secondary RS frame handler 212 identifies secondary RS framesreceived from the secondary RS frame decoder 180 of the basebandprocessor 100 for each row unit, so as to configure an MH TP.Thereafter, the secondary RS frame handler 212 outputs the configured MHTP to the MH TP handler 213.

The MH transport packet (TP) handler 213 extracts a header from each MHTP received from the primary RS frame handler 211 and the secondary RSframe handler 212, thereby determining the data included in thecorresponding MH TP. Then, when the determined data correspond to SIdata (i.e., SI data that are not encapsulated to IP datagrams), thecorresponding data are outputted to the physical adaptation controlsignal handler 216. Alternatively, when the determined data correspondto an IP datagram, the corresponding data are outputted to the IPnetwork stack 220.

The IP network stack 220 processes broadcast data that are beingtransmitted in the form of IP datagrams. More specifically, the IPnetwork stack 220 processes data that are inputted via user datagramprotocol (UDP), real-time transport protocol (RTP), real-time transportcontrol protocol (RTCP), asynchronous layered coding/layered codingtransport (ALC/LCT), file delivery over unidirectional transport(FLUTE), and so on. Herein, when the processed data correspond tostreaming data, the corresponding data are outputted to the streaminghandler 230. And, when the processed data correspond to data in a fileformat, the corresponding data are outputted to the file handler 250.Finally, when the processed data correspond to SI-associated data, thecorresponding data are outputted to the SI handler 240.

The SI handler 240 receives and processes SI data having the form of IPdatagrams, which are inputted to the IP network stack 220.

When the inputted data associated with SI correspond to MIME-type data,the inputted data are outputted to the MIME-type handler 260.

The MIME-type handler 260 receives the MIME-type SI data outputted fromthe SI handler 240 and processes the received MIME-type SI data.

The file handler 250 receives data from the IP network stack 220 in anobject format in accordance with the ALC/LCT and FLUTE structures. Thefile handler 250 groups the received data to create a file format.Herein, when the corresponding file includes ESG, the file is outputtedto the ESG handler 270. On the other hand, when the corresponding fileincludes data for other file-based services, the file is outputted tothe presentation controller 330 of the presentation processor 300.

The ESG handler 270 processes the ESG data received from the filehandler 250 and stores the processed ESG data to the storage unit 290.Alternatively, the ESG handler 270 may output the processed ESG data tothe ESG decoder 280, thereby allowing the ESG data to be used by the ESGdecoder 280.

The storage unit 290 stores the system information (SI) received fromthe physical adaptation control signal handler 210 and the ESG handler270 therein. Thereafter, the storage unit 290 transmits the stored SIdata to each block.

The ESG decoder 280 either recovers the ESG data and SI data stored inthe storage unit 290 or recovers the ESG data transmitted from the ESGhandler 270. Then, the ESG decoder 280 outputs the recovered data to thepresentation controller 330 in a format that can be outputted to theuser.

The streaming handler 230 receives data from the IP network stack 220,wherein the format of the received data are in accordance with RTPand/or RTCP structures. The streaming handler 230 extracts audio/videostreams from the received data, which are then outputted to theaudio/video (A/V) decoder 310 of the presentation processor 300. Theaudio/video decoder 310 then decodes each of the audio stream and videostream received from the streaming handler 230.

The display module 320 of the presentation processor 300 receives audioand video signals respectively decoded by the A/V decoder 310. Then, thedisplay module 320 provides the received audio and video signals to theuser through a speaker and/or a screen.

The presentation controller 330 corresponds to a controller managingmodules that output data received by the receiving system to the user.

The channel service manager 340 manages an interface with the user,which enables the user to use channel-based broadcast services, such aschannel map management, channel service connection, and so on.

The application manager 350 manages an interface with a user using ESGdisplay or other application services that do not correspond tochannel-based services.

Data Format Structure

Meanwhile, the data structure used in the mobile broadcasting technologyaccording to the embodiment of the present invention may include a datagroup structure and an RS frame structure, which will now be describedin detail.

FIG. 2 illustrates an exemplary structure of a data group according tothe present invention.

FIG. 2 shows an example of dividing a data group according to the datastructure of the present invention into 10 MH blocks (i.e., MH block 1(B1) to MH block 10 (B10)). In this example, each MH block has thelength of 16 segments.

Referring to FIG. 2, only the RS parity data are allocated to portionsof the previous 5 segments of the MH block 1 (B1) and the next 5segments of the MH block 10 (B10). The RS parity data are excluded inregions A to D of the data group.

More specifically, when it is assumed that one data group is dividedinto regions A, B, C, and D, each MH block may be included in any one ofregion A to region D depending upon the characteristic of each MH blockwithin the data group. Herein, the data group is divided into aplurality of regions to be used for different purposes. Morespecifically, a region of the main service data having no interferenceor a very low interference level may be considered to have a moreresistant (or stronger) receiving performance as compared to regionshaving higher interference levels. Additionally, when using a systeminserting and transmitting known data in the data group, wherein theknown data are known based upon an agreement between the transmittingsystem and the receiving system, and when consecutively long known dataare to be periodically inserted in the mobile service data, the knowndata having a predetermined length may be periodically inserted in theregion having no interference from the main service data (i.e., a regionwherein the main service data are not mixed). However, due tointerference from the main service data, it is difficult to periodicallyinsert known data and also to insert consecutively long known data to aregion having interference from the main service data.

Referring to FIG. 2, MH block 4 (B4) to MH block 7 (B7) correspond toregions without interference of the main service data. MH block 4 (B4)to MH block 7 (B7) within the data group shown in FIG. 2 correspond to aregion where no interference from the main service data occurs. In thisexample, a long known data sequence is inserted at both the beginningand end of each MH block. In the description of the present invention,the region including MH block 4 (B4) to MH block 7 (B7) will be referredto as “region A (=B4+B5+B6+B7)”. As described above, when the data groupincludes region A having a long known data sequence inserted at both thebeginning and end of each MH block, the receiving system is capable ofperforming equalization by using the channel information that can beobtained from the known data. Therefore, the strongest equalizingperformance may be yielded (or obtained) from one of region A to regionD.

In the example of the data group shown in FIG. 2, MH block 3 (B3) and MHblock 8 (B8) correspond to a region having little interference from themain service data. Herein, a long known data sequence is inserted inonly one side of each MH block B3 and B8. More specifically, due to theinterference from the main service data, a long known data sequence isinserted at the end of MH block 3 (B3), and another long known datasequence is inserted at the beginning of MH block 8 (B8). In the presentinvention, the region including MH block 3 (B3) and MH block 8 (B8) willbe referred to as “region B (=B3+B8)”. As described above, when the datagroup includes region B having a long known data sequence inserted atonly one side (beginning or end) of each MH block, the receiving systemis capable of performing equalization by using the channel informationthat can be obtained from the known data. Therefore, a strongerequalizing performance as compared to region C/D may be yielded (orobtained).

Referring to FIG. 2, MH block 2 (B2) and MH block 9 (B9) correspond to aregion having more interference from the main service data as comparedto region B. A long known data sequence cannot be inserted in any sideof MH block 2 (B2) and MH block 9 (B9). Herein, the region including MHblock 2 (B2) and MH block 9 (B9) will be referred to as “region C(=B2+B9)”.

Finally, in the example shown in FIG. 2, MH block 1 (B1) and MH block 10(B10) correspond to a region having more interference from the mainservice data as compared to region C. Similarly, a long known datasequence cannot be inserted in any side of MH block 1 (B1) and MH block10 (B10). Herein, the region including MH block 1 (B1) and MH block 10(B10) will be referred to as “region D (=B1+B10)”. Since region C/D isspaced further apart from the known data sequence, when the channelenvironment undergoes frequent and abrupt changes, the receivingperformance of region C/D may be deteriorated.

Additionally, the data group includes a signaling information areawherein signaling information is assigned (or allocated).

In the present invention, the signaling information area may start fromthe 1^(st) segment of the 4^(th) MH block (B4) to a portion of the2^(nd) segment. According to an embodiment of the present invention, thesignaling information area for inserting signaling information may startfrom the 1^(st) segment of the 4^(th) MH block (B4) to a portion of the2^(nd) segment.

More specifically, 276(=207+69) bytes of the 4^(th) MH block (B4) ineach data group are assigned as the signaling information area. In otherwords, the signaling information area consists of 207 bytes of the1^(st) segment and the first 69 bytes of the 2^(nd) segment of the4^(th) MH block (B4). The 1^(st) segment of the 4^(th) MH block (B4)corresponds to the 17^(th) or 173^(rd) segment of a VSB field.

Herein, the signaling information may be identified by two differenttypes of signaling channels: a transmission parameter channel (TPC) anda fast information channel (FIC).

Herein, the TPC data may include at least one of an MH ensemble ID, anMH sub-frame number, a total number of MH groups (TNoG), an RS framecontinuity counter, a column size of RS frame (N), and an FIC versionnumber. However, the TPC data (or information) presented herein aremerely exemplary. And, since the adding or deleting of signalinginformation included in the TPC data may be easily adjusted and modifiedby one skilled in the art, the present invention will, therefore, not belimited to the examples set forth herein. Furthermore, the FIC isprovided to enable a fast service acquisition of data receivers, and theFIC includes cross layer information between the physical layer and theupper layer(s).

For example, when the data group includes 6 known data sequences, asshown in FIG. 2, the signaling information area is located between thefirst known data sequence and the second known data sequence. Morespecifically, the first known data sequence is inserted in the last 2segments of the 3^(rd) MH block (B3), and the second known data sequencein inserted in the 2^(nd) and 3^(rd) segments of the 4^(th) MH block(B4). Furthermore, the 3^(rd) to 6^(th) known data sequences arerespectively inserted in the last 2 segments of each of the 4^(th),5^(th), 6^(th), and 7^(th) MH blocks (B4, B5, B6, and B7). The 1^(st)and 3^(rd) to 6^(th) known data sequences are spaced apart by 16segments.

FIG. 3 illustrates an RS frame according to an embodiment of the presentinvention.

The RS frame shown in FIG. 3 corresponds to a collection of one or moredata groups. The RS frame is received for each MH frame in a conditionwhere the receiving system receives the FIC and processes the receivedFIC and where the receiving system is switched to a time-slicing mode sothat the receiving system can receive MH ensembles including ESG entrypoints. Each RS frame includes IP streams of each service or ESG, andSMT section data may exist in all RS frames.

The RS frame according to the embodiment of the present inventionconsists of at least one MH transport packet (TP) Herein, the MH TPincludes an MH header and an MH payload.

The MH payload may include mobile service data as well as signalingdata. More specifically, an MH payload may include only mobile servicedata, or may include only signaling data, or may include both mobileservice data and signaling data.

According to the embodiment of the present invention, the MH header mayidentify (or distinguish) the data types included in the MH payload.More specifically, when the MH TP includes a first MH header, thisindicates that the MH payload includes only the signaling data. Also,when the MH TP includes a second MH header, this indicates that the MHpayload includes both the signaling data and the mobile service data.Finally, when MH TP includes a third MH header, this indicates that theMH payload includes only the mobile service data.

In the example shown in FIG. 3, the RS frame is assigned with IPdatagrams (IP datagram 1 and IP datagram 2) for two service types.

Data Transmission Structure

FIG. 4 illustrates a structure of a MH frame for transmitting andreceiving mobile service data according to the present invention. In theexample shown in FIG. 4, one MH frame consists of 5 sub-frames, whereineach sub-frame includes 16 slots. In this case, the MH frame accordingto the present invention includes 5 sub-frames and 80 slots.

Also, in a packet level, one slot is configured of 156 data packets(i.e., transport stream packets), and in a symbol level, one slot isconfigured of 156 data segments. Herein, the size of one slotcorresponds to one half (½) of a VSB field. More specifically, since one207-byte data packet has the same amount of data as a data segment, adata packet prior to being interleaved may also be used as a datasegment. At this point, two VSB fields are grouped to form a VSB frame.

FIG. 5 illustrates an exemplary structure of a VSB frame, wherein oneVSB frame consists of 2 VSB fields (i.e., an odd field and an evenfield). Herein, each VSB field includes a field synchronization segmentand 312 data segments.

The slot corresponds to a basic time unit for multiplexing the mobileservice data and the main service data. Herein, one slot may eitherinclude the mobile service data or be configured only of the mainservice data.

If the first 118 data packets within the slot correspond to a datagroup, the remaining 38 data packets become the main service datapackets. In another example, when no data group exists in a slot, thecorresponding slot is configured of 156 main service data packets.

Meanwhile, when the slots are assigned to a VSB frame, an off-set existsfor each assigned position.

FIG. 6 illustrates a mapping example of the positions to which the first4 slots of a sub-frame are assigned with respect to a VSB frame in aspatial area. And, FIG. 7 illustrates a mapping example of the positionsto which the first 4 slots of a sub-frame are assigned with respect to aVSB frame in a chronological (or time) area.

Referring to FIG. 6 and FIG. 7, a 38^(th) data packet (TS packet #37) ofa 1^(st) slot (Slot #0) is mapped to the 1^(st) data packet of an oddVSB field. A 38^(th) data packet (TS packet #37) of a 2^(nd) slot (Slot#1) is mapped to the 157^(th) data packet of an odd VSB field. Also, a38^(th) data packet (TS packet #37) of a 3^(rd) slot (Slot #2) is mappedto the 1^(st) data packet of an even VSB field. And, a 38^(th) datapacket (TS packet #37) of a 4^(th) slot (Slot #3) is mapped to the157^(th) data packet of an even VSB field. Similarly, the remaining 12slots within the corresponding sub-frame are mapped in the subsequentVSB frames using the same method.

FIG. 8 illustrates an exemplary assignment order of data groups beingassigned to one of 5 sub-frames, wherein the 5 sub-frames configure anMH frame. For example, the method of assigning data groups may beidentically applied to all MH frames or differently applied to each MHframe. Furthermore, the method of assigning data groups may beidentically applied to all sub-frames or differently applied to eachsub-frame. At this point, when it is assumed that the data groups areassigned using the same method in all sub-frames of the corresponding MHframe, the total number of data groups being assigned to an MH frame isequal to a multiple of ‘5’.

According to the embodiment of the present invention, a plurality ofconsecutive data groups is assigned to be spaced as far apart from oneanother as possible within the sub-frame. Thus, the system can becapable of responding promptly and effectively to any burst error thatmay occur within a sub-frame.

For example, when it is assumed that 3 data groups are assigned to asub-frame, the data groups are assigned to a 1^(st) slot (Slot #0), a5^(th) slot (Slot #4), and a 9^(th) slot (Slot #8) in the sub-frame,respectively. FIG. 8 illustrates an example of assigning 16 data groupsin one sub-frame using the above-described pattern (or rule). In otherwords, each data group is serially assigned to 16 slots corresponding tothe following numbers: 0, 8, 4, 12, 1, 9, 5, 13, 2, 10, 6, 14, 3, 11, 7,and 15. Equation 1 below shows the above-described rule (or pattern) forassigning data groups in a sub-frame.

$\begin{matrix}{{j = {\left( {{4\; i} + 0} \right)\mspace{14mu}{mod}\mspace{14mu} 16}}{{Herein},\text{}\begin{matrix}{0 = 0} & {{{{if}\mspace{14mu} i} < 4},} \\{0 = 2} & {{{{else}\mspace{14mu}{if}\mspace{14mu} i} < 8},} \\{0 = 1} & {{{{else}\mspace{14mu}{if}\mspace{14mu} i} < 12},} \\{0 = 3} & {{else}.}\end{matrix}}} & {{Equation}\mspace{14mu} 1}\end{matrix}$

Herein, j indicates the slot number within a sub-frame. The value of jmay range from 0 to 15 (i.e., 0≦j≦15). Also, variable i indicates thedata group number. The value of i may range from 0 to 15 (i.e., 0≦i≦15).

In the present invention, a collection of data groups included in a MHframe will be referred to as a “parade”. Based upon the RS frame mode,the parade transmits data of at least one specific RS frame.

The mobile service data within one RS frame may be assigned either toall of regions A/B/C/D within the corresponding data group, or to atleast one of regions A/B/C/D. In the embodiment of the presentinvention, the mobile service data within one RS frame may be assignedeither to all of regions A/B/C/D, or to at least one of regions A/B andregions C/D. If the mobile service data are assigned to the latter case(i.e., one of regions A/B and regions C/D), the RS frame being assignedto regions A/B and the RS frame being assigned to regions C/D within thecorresponding data group are different from one another. According tothe embodiment of the present invention, the RS frame being assigned toregions A/B within the corresponding data group will be referred to as a“primary RS frame”, and the RS frame being assigned to regions C/Dwithin the corresponding data group will be referred to as a “secondaryRS frame”, for simplicity. Also, the primary RS frame and the secondaryRS frame form (or configure) one parade. More specifically, when themobile service data within one RS frame are assigned either to all ofregions A/B/C/D within the corresponding data group, one paradetransmits one RS frame. Conversely, when the mobile service data withinone RS frame are assigned either to at least one of regions A/B andregions C/D, one parade may transmit up to 2 RS frames.

More specifically, the RS frame mode indicates whether a paradetransmits one RS frame, or whether the parade transmits two RS frames.Such RS frame mode is transmitted as the above-described TPC data.

Table 1 below shows an example of the RS frame mode.

TABLE 1 RS frame mode (2 bits) Description 00 There is only one primaryRS frame for all group regions 01 There are two separate RS frames.Primary RS frame for group regions A and B Secondary RS frame for groupregions C and D 10 Reserved 11 Reserved

Table 1 illustrates an example of allocating 2 bits in order to indicatethe RS frame mode. For example, referring to Table 1, when the RS framemode value is equal to ‘00’, this indicates that one parade transmitsone RS frame. And, when the RS frame mode value is equal to ‘01’, thisindicates that one parade transmits two RS frames, i.e., the primary RSframe and the secondary RS frame. More specifically, when the RS framemode value is equal to ‘01’, data of the primary RS frame for regionsA/B are assigned and transmitted to regions A/B of the correspondingdata group. Similarly, data of the secondary RS frame for regions C/Dare assigned and transmitted to regions C/D of the corresponding datagroup.

As described in the assignment of data groups, the parades are alsoassigned to be spaced as far apart from one another as possible withinthe sub-frame. Thus, the system can be capable of responding promptlyand effectively to any burst error that may occur within a sub-frame.

Furthermore, the method of assigning parades may be identically appliedto all MH frames or differently applied to each MH frame. According tothe embodiment of the present invention, the parades may be assigneddifferently for each MH frame and identically for all sub-frames withinan MH frame. More specifically, the MH frame structure may vary by MHframe units. Thus, an ensemble rate may be adjusted on a more frequentand flexible basis.

FIG. 9 illustrates an example of multiple data groups of a single paradebeing assigned (or allocated) to an MH frame. More specifically, FIG. 9illustrates an example of a plurality of data groups included in asingle parade, wherein the number of data groups included in a sub-frameis equal to ‘3’, being allocated to an MH frame.

Referring to FIG. 9, 3 data groups are sequentially assigned to asub-frame at a cycle period of 4 slots. Accordingly, when this processis equally performed in the 5 sub-frames included in the correspondingMH frame, 15 data groups are assigned to a single MH frame. Herein, the15 data groups correspond to data groups included in a parade.Therefore, since one sub-frame is configured of 4 VSB frame, and since 3data groups are included in a sub-frame, the data group of thecorresponding parade is not assigned to one of the 4 VSB frames within asub-frame.

For example, when it is assumed that one parade transmits one RS frame,and that a RS frame encoder (not shown) included in the transmittingsystem performs RS-encoding on the corresponding RS frame, therebyadding 24 bytes of parity data to the corresponding RS frame andtransmitting the processed RS frame, the parity data occupyapproximately 11.37% (=24/(187+24)×100) of the total code word length.Meanwhile, when one sub-frame includes 3 data groups, and when the datagroups included in the parade are assigned, as shown in FIG. 9, a totalof 15 data groups form an RS frame. Accordingly, even when an erroroccurs in an entire data group due to a burst noise within a channel,the percentile is merely 6.67% (=1/15×100). Therefore, the receivingsystem may correct all errors by performing an erasure RS decodingprocess. More specifically, when the erasure RS decoding is performed, anumber of channel errors corresponding to the number of RS parity bytesmay be corrected. By doing so, the receiving system may correct theerror of at least one data group within one parade. Thus, the minimumburst noise length correctable by a RS frame is over 1 VSB frame.

Meanwhile, when data groups of a parade are assigned as shown in FIG. 9,either main service data may be assigned between each data group, ordata groups corresponding to different parades may be assigned betweeneach data group. More specifically, data groups corresponding tomultiple parades may be assigned to one MH frame.

Basically, the method of assigning data groups corresponding to multipleparades is very similar to the method of assigning data groupscorresponding to a single parade. In other words, data groups includedin other parades that are to be assigned to an MH frame are alsorespectively assigned according to a cycle period of 4 slots.

At this point, data groups of a different parade may be sequentiallyassigned to the respective slots in a circular method. Herein, the datagroups are assigned to slots starting from the ones to which data groupsof the previous parade have not yet been assigned.

For example, when it is assumed that data groups corresponding to aparade are assigned as shown in FIG. 9, data groups corresponding to thenext parade may be assigned to a sub-frame starting either from the12^(th) slot of a sub-frame. However, this is merely exemplary. Inanother example, the data groups of the next parade may also besequentially assigned to a different slot within a sub-frame at a cycleperiod of 4 slots starting from the 3^(rd) slot.

FIG. 10 illustrates an example of transmitting 3 parades (Parade #0,Parade #1, and Parade #2) to an MH frame. More specifically, FIG. 10illustrates an example of transmitting parades included in one of 5sub-frames, wherein the 5 sub-frames configure one MH frame.

When the 1^(st) parade (Parade #0) includes 3 data groups for eachsub-frame, the positions of each data groups within the sub-frames maybe obtained by substituting values ‘0’ to ‘2’ for i in Equation 1. Morespecifically, the data groups of the 1^(st) parade (Parade #0) aresequentially assigned to the 1^(st), 5^(th), and 9^(th) slots (Slot #0,Slot #4, and Slot #8) within the sub-frame.

Also, when the 2^(nd) parade includes 2 data groups for each sub-frame,the positions of each data groups within the sub-frames may be obtainedby substituting values ‘3’ and ‘4’ for in Equation 1. More specifically,the data groups of the 2^(nd) parade (Parade #1) are sequentiallyassigned to the 2^(nd) and 12^(th) slots (Slot #1 and Slot #11) withinthe sub-frame.

Finally, when the 3^(rd) parade includes 2 data groups for eachsub-frame, the positions of each data groups within the sub-frames maybe obtained by substituting values ‘5’ and ‘6’ for i in Equation 1. Morespecifically, the data groups of the 3^(rd) parade (Parade #2) aresequentially assigned to the 7^(th) and 11^(th) slots (Slot #6 and Slot#10) within the sub-frame.

As described above, data groups of multiple parades may be assigned to asingle MH frame, and, in each sub-frame, the data groups are seriallyallocated to a group space having 4 slots from left to right.

Therefore, a number of groups of one parade per sub-frame (NoG) maycorrespond to any one integer from ‘1’ to ‘8’. Herein, since one MHframe includes 5 sub-frames, the total number of data groups within aparade that can be allocated to an MH frame may correspond to any onemultiple of ‘5’ ranging from ‘5’ to ‘40’.

FIG. 11 illustrates an example of expanding the assignment process of 3parades, shown in FIG. 10, to 5 sub-frames within an MH frame.

FIG. 12 illustrates a data transmission structure according to anembodiment of the present invention, wherein signaling data are includedin a data group so as to be transmitted.

As described above, an MH frame is divided into 5 sub-frames. Datagroups corresponding to a plurality of parades co-exist in eachsub-frame. Herein, the data groups corresponding to each parade aregrouped by MH frame units, thereby configuring a single parade.

The data structure shown in FIG. 12 includes 3 parades, one ESGdedicated channel (EDC) parade (i.e., parade with NoG=1), and 2 serviceparades (i.e., parade with NoG=4 and parade with NoG=3). Also, apredetermined portion of each data group (i.e., 37 bytes/data group) isused for delivering (or sending) FIC information associated with mobileservice data, wherein the FIC information is separately encoded from theRS-encoding process. The FIC region assigned to each data group consistsof one FIC segments. Herein, each segment is interleaved by MH sub-frameunits, thereby configuring an FIC body, which corresponds to a completedFIC transmission structure. However, whenever required, each segment maybe interleaved by MH frame units and not by MH sub-frame units, therebybeing completed in MH frame units.

Meanwhile, the concept of an MH ensemble is applied in the embodiment ofthe present invention, thereby defining a collection (or group) ofservices. Each MH ensemble carries the same QoS and is coded with thesame FEC code. Also, each MH ensemble has the same unique identifier(i.e., ensemble ID) and corresponds to consecutive RS frames.

As shown in FIG. 12, the FIC segment corresponding to each data groupdescribed service information of an MH ensemble to which thecorresponding data group belongs. When FIC segments within a sub-frameare grouped and deinterleaved, all service information of a physicalchannel through which the corresponding FICs are transmitted may beobtained. Therefore, the receiving system may be able to acquire thechannel information of the corresponding physical channel, after beingprocessed with physical channel tuning, during a sub-frame period.

Furthermore, FIG. 12 illustrates a structure further including aseparate EDC parade apart from the service parade and wherein electronicservice guide (ESG) data are transmitted in the 1^(st) slot of eachsub-frame.

Hierarchical Signaling Structure

FIG. 13 illustrates a hierarchical signaling structure according to anembodiment of the present invention. As shown in FIG. 13, the mobilebroadcasting technology according to the embodiment of the presentinvention adopts a signaling method using FIC and SMT. In thedescription of the present invention, the signaling structure will bereferred to as a hierarchical signaling structure.

Hereinafter, a detailed description on how the receiving system accessesa virtual channel via FIC and SMT will now be given with reference toFIG. 13.

The FIC body defined in an MH transport (M1) identifies the physicallocation of each the data stream for each virtual channel and providesvery high level descriptions of each virtual channel.

Being MH ensemble level signaling information, the service map table(SMT) provides MH ensemble level signaling information. The SMT providesthe IP access information of each virtual channel belonging to therespective MH ensemble within which the SMT is carried. The SMT alsoprovides all IP stream component level information required for thevirtual channel service acquisition.

Referring to FIG. 13, each MH ensemble (i.e., Ensemble 0, Ensemble 1, .. . , Ensemble K) includes a stream information on each associated (orcorresponding) virtual channel (e.g., virtual channel 0 IP stream,virtual channel 1 IP stream, and virtual channel 2 IP stream). Forexample, Ensemble 0 includes virtual channel 0 IP stream and virtualchannel 1 IP stream. And, each MH ensemble includes diverse informationon the associated virtual channel (i.e., Virtual Channel 0 Table Entry,Virtual Channel 0 Access Info, Virtual Channel 1 Table Entry, VirtualChannel 1 Access Info, Virtual Channel 2 Table Entry, Virtual Channel 2Access Info, Virtual Channel N Table Entry, Virtual Channel N AccessInfo, and so on).

The FIC body payload includes information on MH ensembles (e.g.,ensemble_id field, and referred to as “ensemble location” in FIG. 13)and information on a virtual channel associated with the correspondingMH ensemble (e.g., when such information corresponds to amajor_channel_num field and a minor_channel_num field, the informationis expressed as Virtual Channel 0, Virtual Channel 1, . . . , VirtualChannel N in FIG. 13).

The application of the signaling structure in the receiving system willnow be described in detail.

When a user selects a channel he or she wishes to view (hereinafter, theuser-selected channel will be referred to as “channel θ” forsimplicity), the receiving system first parses the received FIC. Then,the receiving system acquires information on an MH ensemble (i.e.,ensemble location), which is associated with the virtual channelcorresponding to channel θ (hereinafter, the corresponding MH ensemblewill be referred to as “MH ensemble θ” for simplicity). By acquiringslots only corresponding to the MH ensemble θ using the time-slicingmethod, the receiving system configures ensemble θ. The ensemble θconfigured as described above, includes an SMT on the associated virtualchannels (including channel θ) and IP streams on the correspondingvirtual channels. Therefore, the receiving system uses the SMT includedin the MH ensemble θ in order to acquire various information on channelθ (e.g., Virtual Channel θ Table Entry) and stream access information onchannel θ (e.g., Virtual Channel θ Access Info). The receiving systemuses the stream access information on channel θ to receive only theassociated IP streams, thereby providing channel θ services to the user.

Fast Information Channel (FIC)

The digital broadcast receiving system according to the presentinvention adopts the fast information channel (FIC) for a faster accessto a service that is currently being broadcasted.

More specifically, the FIC handler 215 of FIG. 1 parses the FIC body,which corresponds to an FIC transmission structure, and outputs theparsed result to the physical adaptation control signal handler 216.

FIG. 14 illustrates an exemplary FIC body format according to anembodiment of the present invention. According to the embodiment of thepresent invention, the FIC format consists of an FIC body header and anFIC body payload.

Meanwhile, according to the embodiment of the present invention, dataare transmitted through the FIC body header and the FIC body payload inFIC segment units. Each FIC segment has the size of 37 bytes, and eachFIC segment consists of a 2-byte FIC segment header and a 35-byte FICsegment payload. More specifically, an FIC body configured of an FICbody header and an FIC body payload, is segmented in units of 35 databytes, which are then carried in at least one FIC segment within the FICsegment payload, so as to be transmitted.

In the description of the present invention, an example of inserting oneFIC segment in one data group, which is then transmitted, will be given.In this case, the receiving system receives a slot corresponding to eachdata group by using a time-slicing method.

The signaling decoder 190 included in the receiving system shown in FIG.1 collects each FIC segment inserted in each data group. Then, thesignaling decoder 190 uses the collected FIC segments to created asingle FIC body. Thereafter, the signaling decoder 190 performs adecoding process on the FIC body payload of the created FIC body, sothat the decoded FIC body payload corresponds to an encoded result of asignaling encoder (not shown) included in the transmitting system.Subsequently, the decoded FIC body payload is outputted to the FIChandler 215. The FIC handler 215 parses the FIC data included in the FICbody payload, and then outputs the parsed FIC data to the physicaladaptation control signal handler 216. The physical adaptation controlsignal handler 216 uses the inputted FIC data to perform processesassociated with MH ensembles, virtual channels, SMTs, and so on.

According to an embodiment of the present invention, when an FIC body issegmented, and when the size of the last segmented portion is smallerthan 35 data bytes, it is assumed that the lacking number of data bytesin the FIC segment payload is completed with by adding the same numberof stuffing bytes therein, so that the size of the last FIC segment canbe equal to 35 data bytes.

However, it is apparent that the above-described data byte values (i.e.,37 bytes for the FIC segment, 2 bytes for the FIC segment header, and 35bytes for the FIC segment payload) are merely exemplary, and will,therefore, not limit the scope of the present invention.

FIG. 15 illustrates an exemplary bit stream syntax structure withrespect to an FIC segment according to an embodiment of the presentinvention.

Herein, the FIC segment signifies a unit used for transmitting the FICdata. The FIC segment consists of an FIC segment header and an FICsegment payload. Referring to FIG. 15, the FIC segment payloadcorresponds to the portion starting from the ‘for’ loop statement.Meanwhile, the FIC segment header may include a FIC_type field, anerror_indicator field, an FIC_seg_number field, and anFIC_last_seg_number field. A detailed description of each field will nowbe given.

The FIC_type field is a 2-bit field indicating the type of thecorresponding FIC.

The error_indicator field is a 1-bit field, which indicates whether ornot an error has occurred within the FIC segment during datatransmission. If an error has occurred, the value of the error_indicatorfield is set to ‘1’. More specifically, when an error that has failed tobe recovered still remains during the configuration process of the FICsegment, the error_indicator field value is set to ‘1’. Theerror_indicator field enables the receiving system to recognize thepresence of an error within the FIC data.

The FIC_seg_number field is a 4-bit field. Herein, when a single FICbody is divided into a plurality of FIC segments and transmitted, theFIC_seg_number field indicates the number of the corresponding FICsegment.

Finally, the FIC_last_seg_number field is also a 4-bit field. TheFIC_last_seg_number field indicates the number of the last FIC segmentwithin the corresponding FIC body.

FIG. 16 illustrates an exemplary bit stream syntax structure withrespect to a payload of an FIC segment according to the presentinvention, when an FIC type field value is equal to ‘0’.

According to the embodiment of the present invention, the payload of theFIC segment is divided into 3 different regions.

A first region of the FIC segment payload exists only when theFIC_seg_number field value is equal to ‘0’. Herein, the first region mayinclude a current_next_indicator field, an ESG_version field, and atransport_stream_id field. However, depending upon the embodiment of thepresent invention, it may be assumed that each of the 3 fields existsregardless of the FIC_seg_number field.

The current_next_indicator field is a 1-bit field. Thecurrent_next_indicator field acts as an indicator identifying whetherthe corresponding FIC data carry MH ensemble configuration informationof an MH frame including the current FIC segment, or whether thecorresponding FIC data carry MH ensemble configuration information of anext MH frame.

The ESG_version field is a 5-bit field indicating ESG versioninformation. Herein, by providing version information on the serviceguide providing channel of the corresponding ESG, the ESG_version fieldenables the receiving system to notify whether or not the correspondingESG has been updated.

Finally, the transport_stream_id field is a 16-bit field acting as aunique identifier of a broadcast stream through which the correspondingFIC segment is being transmitted.

A second region of the FIC segment payload corresponds to an ensembleloop region, which includes an ensemble_id field, an SI_version field,and a num_channel field.

More specifically, the ensemble_id field is an 8-bit field indicatingidentifiers of an MH ensemble through which MH services are transmitted.The MH services will be described in more detail in a later process.Herein, the ensemble_id field binds the MH services and the MH ensemble.

The SI_version field is a 4-bit field indicating version information ofSI data included in the corresponding ensemble, which is beingtransmitted within the RS frame.

Finally, the num_channel field is an 8-bit field indicating the numberof virtual channel being transmitted via the corresponding ensemble.

A third region of the FIC segment payload a channel loop region, whichincludes a channel_type field, a channel_activity field, a CA_indicatorfield, a stand_alone_service_indicator field, a major_channel_num field,and a minor_channel_num field.

The channel_type field is a 5-bit field indicating a service type of thecorresponding virtual channel. For example, the channel_type field mayindicates an audio/video channel, an audio/video and data channel, anaudio-only channel, a data-only channel, a file download channel, an ESGdelivery channel, a notification channel, and so on.

The channel_activity field is a 2-bit field indicating activityinformation of the corresponding virtual channel. More specifically, thechannel_activity field may indicate whether the current virtual channelis providing the current service.

The CA_indicator field is a 1-bit field indicating whether or not aconditional access (CA) is applied to the current virtual channel.

The stand_alone_service_indicator field is also a 1-bit field, whichindicates whether the service of the corresponding virtual channelcorresponds to a stand alone service.

The major_channel_num field is an 8-bit field indicating a major channelnumber of the corresponding virtual channel.

Finally, the minor_channel_num field is also an 8-bit field indicating aminor channel number of the corresponding virtual channel.

Service Table Map

FIG. 17 illustrates an exemplary bit stream syntax structure of aservice map table (hereinafter referred to as “SMT”) according to thepresent invention.

According to the embodiment of the present invention, the SMT isconfigured in an MPEG-2 private section format. However, this will notlimit the scope and spirit of the present invention. The SMT accordingto the embodiment of the present invention includes descriptioninformation for each virtual channel within a single MH ensemble. And,additional information may further be included in each descriptor area.

Herein, the SMT according to the embodiment of the present inventionincludes at least one field and is transmitted from the transmittingsystem to the receiving system.

As described in FIG. 3, the SMT section may be transmitted by beingincluded in the MH TP within the RS frame. In this case, each of the RSframe decoders 170 and 180, shown in FIG. 1, decodes the inputted RSframe, respectively. Then, each of the decoded RS frames is outputted tothe respective RS frame handler 211 and 212. Thereafter, each RS framehandler 211 and 212 identifies the inputted RS frame by row units, so asto create an MH TP, thereby outputting the created MH TP to the MH TPhandler 213.

When it is determined that the corresponding MH TP includes an SMTsection based upon the header in each of the inputted MH TP, the MH TPhandler 213 parses the corresponding SMT section, so as to output the SIdata within the parsed SMT section to the physical adaptation controlsignal handler 216. However, this is limited to when the SMT is notencapsulated to IP datagrams.

Meanwhile, when the SMT is encapsulated to IP datagrams, and when it isdetermined that the corresponding MH TP includes an SMT section basedupon the header in each of the inputted MH TP, the MH TP handler 213outputs the SMT section to the IP network stack 220. Accordingly, the IPnetwork stack 220 performs IP and UDP processes on the inputted SMTsection and, then, outputs the processed SMT section to the SI handler240. The SI handler 240 parses the inputted SMT section and controls thesystem so that the parsed SI data can be stored in the storage unit 290.

The following corresponds to example of the fields that may betransmitted through the SMT.

A table_id field corresponds to an 8-bit unsigned integer number, whichindicates the type of table section. The table_id field allows thecorresponding table to be defined as the service map table (SMT).

An ensemble_id field is an 8-bit unsigned integer field, whichcorresponds to an ID value associated to the corresponding MH ensemble.Herein, the ensemble_id field may be assigned with a value ranging fromrange ‘0x00’ to ‘0x3F’. It is preferable that the value of theensemble_id field is derived from the parade_id of the TPC data, whichis carried from the baseband processor of MH physical layer subsystem.When the corresponding MH ensemble is transmitted through (or carriedover) the primary RS frame, a value of ‘0’ may be used for the mostsignificant bit (MSB), and the remaining 7 bits are used as theparade_id value of the associated MH parade (i.e., for the leastsignificant 7 bits). Alternatively, when the corresponding MH ensembleis transmitted through (or carried over) the secondary RS frame, a valueof ‘1’ may be used for the most significant bit (MSB).

A num_channels field is an 8-bit field, which specifies the number ofvirtual channels in the corresponding SMT section.

Meanwhile, the SMT according to the embodiment of the present inventionprovides information on a plurality of virtual channels using the ‘for’loop statement.

A major_channel_num field corresponds to an 8-bit field, whichrepresents the major channel number associated with the correspondingvirtual channel. Herein, the major_channel_num field may be assignedwith a value ranging from ‘0x00’ to ‘0xFF’.

A minor_channel_num field corresponds to an 8-bit field, whichrepresents the minor channel number associated with the correspondingvirtual channel. Herein, the minor_channel_num field may be assignedwith a value ranging from ‘0x00’ to ‘0xFF’.

A short_channel_name field indicates the short name of the virtualchannel. The service_id field is a 16-bit unsigned integer number (orvalue), which identifies the virtual channel service.

A service_type field is a 6-bit enumerated type field, which designatesthe type of service carried in the corresponding virtual channel asdefined in Table 2 below.

TABLE 2 0x00 [Reserved] 0x01 MH_digital_television field: the virtualchannel carries television programming (audio, video and optionalassociated data) conforming to ATSC standards. 0x02 MH_audio field: thevirtual channel carries audio programming (audio service and optionalassociated data) conforming to ATSC standards. 0x03 MH_data_only_servicefield: the virtual channel carries a data service conforming to ATSCstandards, but no video or audio component. 0x04 to [Reserved for futureATSC usage] 0xFF

A virtual_channel_activity field is a 2-bit enumerated field identifyingthe activity status of the corresponding virtual channel. When the mostsignificant bit (MSB) of the virtual_channel_activity field is ‘1’, thevirtual channel is active, and when the most significant bit (MSB) ofthe virtual_channel_activity field is ‘0’, the virtual channel isinactive. Also, when the least significant bit (LSB) of thevirtual_channel_activity field is ‘1’, the virtual channel is hidden(when set to 1), and when the least significant bit (LSB) of thevirtual_channel_activity field is ‘0’, the virtual channel is nothidden.

A num_components field is a 5-bit field, which specifies the number ofIP stream components in the corresponding virtual channel.

An IP_version_flag field corresponds to a 1-bit indicator. Morespecifically, when the value of the IP_version_flag field is set to ‘1’,this indicates that a source_IP_address field, avirtual_channel_target_IP_address field, and acomponent_target_IP_address field are IPv6 addresses. Alternatively,when the value of the IP_version_flag field is set to ‘0’, thisindicates that the source_IP_address field, thevirtual_channel_target_IP_address field, and thecomponent_target_IP_address field are IPv4.

A source_IP_address_flag field is a 1-bit Boolean flag, which indicates,when set, that a source IP address of the corresponding virtual channelexist for a specific multicast source.

A virtual_channel_target_IP_address_flag field is a 1-bit Boolean flag,which indicates, when set, that the corresponding IP stream component isdelivered through IP datagrams with target IP addresses different fromthe virtual_channel_target_IP_address. Therefore, when the flag is set,the receiving system (or receiver) uses the component_target_IP_addressas the target_IP_address in order to access the corresponding IP streamcomponent. Accordingly, the receiving system (or receiver) may ignorethe virtual_channel_target_IP_address field included in the num_channelsloop.

The source_IP_address field corresponds to a 32-bit or 128-bit field.Herein, the source_IP_address field will be significant (or present),when the value of the source_IP_address_flag field is set to ‘1’.However, when the value of the source_IP_address_flag field is set to‘0’, the source_IP_address field will become insignificant (or absent).More specifically, when the source_IP_address_flag field value is set to‘1’, and when the IP_version_flag field value is set to ‘0’, thesource_IP_address field indicates a 32-bit IPv4 address, which shows thesource of the corresponding virtual channel. Alternatively, when theIP_version_flag field value is set to ‘1’, the source_IP_address fieldindicates a 128-bit IPv6 address, which shows the source of thecorresponding virtual channel.

The virtual_channel_target_IP_address field also corresponds to a 32-bitor 128-bit field. Herein, the virtual_channel_target_IP_address fieldwill be significant (or present), when the value of thevirtual_channel_target_IP_address_flag field is set to ‘1’. However,when the value of the virtual_channel_target_IP_address_flag field isset to ‘0’, the virtual_channel_target_IP_address field will becomeinsignificant (or absent). More specifically, when thevirtual_channel_target_IP_address_flag field value is set to ‘1’, andwhen the IP_version_flag field value is set to ‘0’, thevirtual_channel_target_IP_address field indicates a 32-bit target IPv4address associated to the corresponding virtual channel. Alternatively,when the virtual_channel_target_IP_address_flag field value is set to‘1’, and when the IP_version_flag field value is set to ‘1’, thevirtual_channel_target_IP_address field indicates a 64-bit target IPv6address associated to the corresponding virtual channel. If thevirtual_channel_target_IP_address field is insignificant (or absent),the component_target_IP_address field within the num_channels loopshould become significant (or present). And, in order to enable thereceiving system to access the IP stream component, thecomponent_target_IP_address field should be used.

Meanwhile, the SMT according to the embodiment of the present inventionuses a ‘for’ loop statement in order to provide information on aplurality of components.

Herein, an RTP_payload_type field, which is assigned with 7 bits,identifies the encoding format of the component based upon Table 3 shownbelow. When the IP stream component is not encapsulated to RTP, theRTP_payload_type field shall be ignored (or deprecated).

Table 3 below shows an example of the RTP_payload_type.

TABLE 3 RTP_payload_type Meaning 35 AVC video 36 MH audio 37 to 72[Reserved for future ATSC use]

A component_target_IP_address_flag field is a 1-bit Boolean flag, whichindicates, when set, that the corresponding IP stream component isdelivered through IP datagrams with target IP addresses different fromthe virtual_channel_target_IP_address. Furthermore, when thecomponent_target_IP_address_flag is set, the receiving system (orreceiver) uses the component_target_IP_address field as the target IPaddress for accessing the corresponding IP stream component.Accordingly, the receiving system (or receiver) will ignore thevirtual_channel_target_IP_address field included in the num_channelsloop.

The component_target_IP_address field corresponds to a 32-bit or 128-bitfield. Herein, when the value of the IP_version_flag field is set to‘0’, the component_target_IP_address field indicates a 32-bit targetIPv4 address associated to the corresponding IP stream component. And,when the value of the IP_version_flag field is set to ‘1’, thecomponent_target_IP_address field indicates a 128-bit target IPv6address associated to the corresponding IP stream component.

A port_num_count field is a 6-bit field, which indicates the number ofUDP ports associated with the corresponding IP stream component. Atarget UDP port number value starts from the target_UDP_port_num fieldvalue and increases (or is incremented) by 1. For the RTP stream, thetarget UDP port number should start from the target_UDP_port_num fieldvalue and shall increase (or be incremented) by 2. This is toincorporate RTCP streams associated with the RTP streams.

A target_UDP_port_num field is a 16-bit unsigned integer field, whichrepresents the target UDP port number for the corresponding IP streamcomponent. When used for RTP streams, the value of thetarget_UDP_port_num field shall correspond to an even number. And, thenext higher value shall represent the target UDP port number of theassociated RTCP stream.

A component_level_descriptor( ) represents zero or more descriptorsproviding additional information on the corresponding IP streamcomponent.

A virtual_channel_level_descriptor( ) represents zero or moredescriptors providing additional information for the correspondingvirtual channel.

An ensemble_level_descriptor( ) represents zero or more descriptorsproviding additional information for the MH ensemble, which is describedby the corresponding SMT.

FIG. 18 illustrates an exemplary bit stream syntax structure of an MHaudio descriptor according to the present invention.

When at least one audio service is present as a component of the currentevent, the MH_audio_descriptor( ) shall be used as acomponent_level_descriptor of the SMT. The MH_audio_descriptor( ) may becapable of informing the system of the audio language type and stereomode status. If there is no audio service associated with the currentevent, then it is preferable that the MH_audio_descriptor( ) isconsidered to be insignificant (or absent) for the current event.

Each field shown in the bit stream syntax of FIG. 18 will now bedescribed in detail.

A descriptor_tag field is an 8-bit unsigned integer having a TBD value,which indicates that the corresponding descriptor is theMH_audio_descriptor( ).

A descriptor_length field is also an 8-bit unsigned integer, whichindicates the length (in bytes) of the portion immediately following thedescriptor_length field up to the end of the MH_audio_descriptor( ).

A channel_configuration field corresponds to an 8-bit field indicatingthe number and configuration of audio channels. The values ranging from‘1’ to ‘6’ respectively indicate the number and configuration of audiochannels as given for “Default bit stream index number” in Table 42 ofISO/IEC 13818-7:2006. All other values indicate that the number andconfiguration of audio channels are undefined.

A sample_rate_code field is a 3-bit field, which indicates the samplerate of the encoded audio data. Herein, the indication may correspond toone specific sample rate, or may correspond to a set of values thatinclude the sample rate of the encoded audio data as defined in TableA3.3 of ATSC A/52B.

A bit_rate_code field corresponds to a 6-bit field. Herein, among the 6bits, the lower 5 bits indicate a nominal bit rate. More specifically,when the most significant bit (MSB) is ‘0’, the corresponding bit rateis exact. On the other hand, when the most significant bit (MSB) is ‘0’,the bit rate corresponds to an upper limit as defined in Table A3.4 ofATSC A/53B.

An ISO_(—)639_language_code field is a 24-bit (i.e., 3-byte) fieldindicating the language used for the audio stream component, inconformance with ISO 639.2/B [x]. When a specific language is notpresent in the corresponding audio stream component, the value of eachbyte will be set to ‘0x00’.

FIG. 19 illustrates an exemplary bit stream syntax structure of an MHRTP payload type descriptor according to the present invention.

The MH_RTP_payload_type_descriptor( ) specifies the RTP payload type.Yet, the MH_RTP_payload_type_descriptor( ) exists only when the dynamicvalue of the RTP_payload_type field within the num_components loop ofthe SMT is in the range of ‘96’ to ‘127’. TheMH_RTP_payload_type_descriptor( ) is used as acomponent_level_descriptor of the SMT.

The MH_RTP_payload_type_descriptor translates (or matches) a dynamicRTP_payload_type field value into (or with) a MIME type. Accordingly,the receiving system (or receiver) may collect (or gather) the encodingformat of the IP stream component, which is encapsulated in RTP.

The fields included in the MH_RTP_payload_type_descriptor( ) will now bedescribed in detail.

A descriptor_tag field corresponds to an 8-bit unsigned integer havingthe value TBD, which identifies the current descriptor as theMH_RTP_payload_type_descriptor( ).

A descriptor_length field also corresponds to an 8-bit unsigned integer,which indicates the length (in bytes) of the portion immediatelyfollowing the descriptor_length field up to the end of theMH_RTP_payload_type_descriptor( ).

An RTP_payload_type field corresponds to a 7-bit field, which identifiesthe encoding format of the IP stream component. Herein, the dynamicvalue of the RTP_payload_type field is in the range of ‘96’ to ‘127’.

A MIME_type_length field specifies the length (in bytes) of a MIME_typefield.

The MIME_type field indicates the MIME type corresponding to theencoding format of the IP stream component, which is described by theMH_RTP_payload_type_descriptor( ).

FIG. 20 illustrates an exemplary bit stream syntax structure of an MHcurrent event descriptor according to the present invention.

The MH_current_event_descriptor( ) shall be used as thevirtual_channel_level_descriptor( ) within the SMT. Herein, theMH_current_event_descriptor( ) provides basic information on the currentevent (e.g., the start time, duration, and title of the current event,etc.), which is transmitted via the respective virtual channel.

The fields included in the MH_current_event_descriptor( ) will now bedescribed in detail.

A descriptor_tag field corresponds to an 8-bit unsigned integer havingthe value TBD, which identifies the current descriptor as theMH_current_event_descriptor( ).

A descriptor_length field also corresponds to an 8-bit unsigned integer,which indicates the length (in bytes) of the portion immediatelyfollowing the descriptor_length field up to the end of theMH_current_event_descriptor( ).

A current_event_start_time field corresponds to a 32-bit unsignedinteger quantity. The current_event_start_time field represents thestart time of the current event and, more specifically, as the number ofGPS seconds since 00:00:00 UTC, Jan. 6, 1980.

A current_event_duration field corresponds to a 24-bit field. Herein,the current_event_duration field indicates the duration of the currentevent in hours, minutes, and seconds (wherein the format is in 6 digits,4-bit BCD=24 bits).

A title_length field specifies the length (in bytes) of a title_textfield. Herein, the value ‘0’ indicates that there are no titles existingfor the corresponding event.

The title_text field indicates the title of the corresponding event inevent title in the format of a multiple string structure as defined inATSC A/65C [x].

FIG. 21 illustrates an exemplary bit stream syntax structure of an MHnext event descriptor according to the present invention.

The optional MH_next_event_descriptor( ) shall be used as thevirtual_channel_level_descriptor( ) within the SMT. Herein, theMH_next_event_descriptor( ) provides basic information on the next event(e.g., the start time, duration, and title of the next event, etc.),which is transmitted via the respective virtual channel.

The fields included in the MH_next_event_descriptor( ) will now bedescribed in detail.

A descriptor_tag field corresponds to an 8-bit unsigned integer havingthe value TBD, which identifies the current descriptor as theMH_next_event_descriptor( ).

A descriptor_length field also corresponds to an 8-bit unsigned integer,which indicates the length (in bytes) of the portion immediatelyfollowing the descriptor_length field up to the end of theMH_next_event_descriptor( ).

A next_event_start_time field corresponds to a 32-bit unsigned integerquantity. The next_event_start_time field represents the start time ofthe next event and, more specifically, as the number of GPS secondssince 00:00:00 UTC, Jan. 6, 1980.

A next_event_duration field corresponds to a 24-bit field. Herein, thenext_event_duration field indicates the duration of the next event inhours, minutes, and seconds (wherein the format is in 6 digits, 4-bitBCD=24 bits).

A title_length field specifies the length (in bytes) of a title_textfield. Herein, the value ‘0’ indicates that there are no titles existingfor the corresponding event.

The title_text field indicates the title of the corresponding event inevent title in the format of a multiple string structure as defined inATSC A/65C [x].

FIG. 22 illustrates an exemplary bit stream syntax structure of an MHsystem time descriptor according to the present invention.

The MH_system_time_descriptor( ) shall be used as theensemble_level_descriptor( ) within the SMT. Herein, theMH_system_time_descriptor( ) provides information on current time anddate. The MH_system_time_descriptor( ) also provides information on thetime zone in which the transmitting system (or transmitter) transmittingthe corresponding broadcast stream is located, while taking intoconsideration the mobile/portable characteristics of the MH servicedata.

The fields included in the MH_system_time_descriptor( ) will now bedescribed in detail.

A descriptor_tag field corresponds to an 8-bit unsigned integer havingthe value TBD, which identifies the current descriptor as theMH_system_time_descriptor( ).

A descriptor_length field also corresponds to an 8-bit unsigned integer,which indicates the length (in bytes) of the portion immediatelyfollowing the descriptor_length field up to the end of theMH_system_time_descriptor( ).

A system_time field corresponds to a 32-bit unsigned integer quantity.The system_time field represents the current system time and, morespecifically, as the number of GPS seconds since 00:00:00 UTC, Jan. 6,1980.

A GPS_UTC_offset field corresponds to an 8-bit unsigned integer, whichdefines the current offset in whole seconds between GPS and UTC timestandards. In order to convert GPS time to UTC time, the GPS_UTC_offsetis subtracted from GPS time. Whenever the International Bureau ofWeights and Measures decides that the current offset is too far inerror, an additional leap second may be added (or subtracted).Accordingly, the GPS_UTC_offset field value will reflect the change.

A time_zone_offset_polarity field is a 1-bit field, which indicateswhether the time of the time zone, in which the broadcast station islocated, exceeds (or leads or is faster) or falls behind (or lags or isslower) than the UTC time. When the value of thetime_zone_offset_polarity field is equal to ‘0’, this indicates that thetime on the current time zone exceeds the UTC time. Therefore, atime_zone_offset field value is added to the UTC time value. Conversely,when the value of the time_zone_offset_polarity field is equal to ‘1’,this indicates that the time on the current time zone falls behind theUTC time. Therefore, the time_zone_offset field value is subtracted fromthe UTC time value.

The time_zone_offset field is a 31-bit unsigned integer quantity. Morespecifically, the time_zone_offset field represents, in GPS seconds, thetime offset of the time zone in which the broadcast station is located,when compared to the UTC time.

A daylight_savings field corresponds to a 16-bit field providinginformation on the Summer Time (i.e., the Daylight Savings Time).

A time_zone field corresponds to a (5×8)-bit field indicating the timezone, in which the transmitting system (or transmitter) transmitting thecorresponding broadcast stream is located.

FIG. 23 illustrates segmentation and encapsulation processes of aservice map table (SMT) according to the present invention.

According to the present invention, the SMT is encapsulated to UDP,while including a target IP address and a target UDP port number withinthe IP datagram. More specifically, the SMT is first segmented into apredetermined number of sections, then encapsulated to a UDP header, andfinally encapsulated to an IP header.

In addition, the SMT section provides signaling information on allvirtual channel included in the MH ensemble including the correspondingSMT section. At least one SMT section describing the MH ensemble isincluded in each RS frame included in the corresponding MH ensemble.Finally, each SMT section is identified by an ensemble_id included ineach section.

According to the embodiment of the present invention, by informing thereceiving system of the target IP address and target UDP port number,the corresponding data (i.e., target IP address and target UDP portnumber) may be parsed without having the receiving system to request forother additional information.

FIG. 24 illustrates a flow chart for accessing a virtual channel usingFIC and SMT according to the present invention.

More specifically, a physical channel is tuned (S501). And, when it isdetermined that an MH signal exists in the tuned physical channel(S502), the corresponding MH signal is demodulated (S503). Additionally,FIC segments are grouped from the demodulated MH signal in sub-frameunits (S504 and S505).

According to the embodiment of the present invention, an FIC segment isinserted in a data group, so as to be transmitted. More specifically,the FIC segment corresponding to each data group described serviceinformation on the MH ensemble to which the corresponding data groupbelongs. When the FIC segments are grouped in sub-frame units and, then,deinterleaved, all service information on the physical channel throughwhich the corresponding FIC segment is transmitted may be acquired.Therefore, after the tuning process, the receiving system may acquirechannel information on the corresponding physical channel during asub-frame period. Once the FIC segments are grouped, in S504 and S505, abroadcast stream through which the corresponding FIC segment is beingtransmitted is identified (S506). For example, the broadcast stream maybe identified by parsing the transport_stream_id field of the FIC body,which is configured by grouping the FIC segments.

Furthermore, an ensemble identifier, a major channel number, a minorchannel number, channel type information, and so on, are extracted fromthe FIC body (S507). And, by using the extracted ensemble information,only the slots corresponding to the designated ensemble are acquired byusing the time-slicing method, so as to configure an ensemble (S508).

Subsequently, the RS frame corresponding to the designated ensemble isdecoded (S509), and an IP socket is opened for SMT reception (S510).

According to the example given in the embodiment of the presentinvention, the SMT is encapsulated to UDP, while including a target IPaddress and a target UDP port number within the IP datagram. Morespecifically, the SMT is first segmented into a predetermined number ofsections, then encapsulated to a UDP header, and finally encapsulated toan IP header. According to the embodiment of the present invention, byinforming the receiving system of the target IP address and target UDPport number, the receiving system parses the SMT sections and thedescriptors of each SMT section without requesting for other additionalinformation (S511).

The SMT section provides signaling information on all virtual channelincluded in the MH ensemble including the corresponding SMT section. Atleast one SMT section describing the MH ensemble is included in each RSframe included in the corresponding MH ensemble. Also, each SMT sectionis identified by an ensemble_id included in each section.

Furthermore each SMT provides IP access information on each virtualchannel subordinate to the corresponding MH ensemble including each SMT.Finally, the SMT provides IP stream component level information requiredfor the servicing of the corresponding virtual channel.

Therefore, by using the information parsed from the SMT, the IP streamcomponent belonging to the virtual channel requested for reception maybe accessed (S513). Accordingly, the service associated with thecorresponding virtual channel is provided to the user (S514).

Meanwhile, the present invention relates to acquiring access informationon an IP-based virtual channel service through an SMT and its respectivedescriptors. Herein, the virtual channel service, mobile service, and MHservice are all used in the same meaning.

More specifically, the SMT is included in an RS frame, which transmitsmobile service data corresponding to a single MH ensemble, so as to bereceived. The SMT includes signaling information on the virtual channeland IP-based mobile service, which are included in the MH ensemble,through which the corresponding SMT is transmitted (or delivered).Furthermore, the SMT may include a plurality of descriptors.

The SMT according to an embodiment of the present invention may includea session description protocol (SDP) reference descriptor. And, in thiscase, the digital broadcast receiving system may recognize (oracknowledge) the corresponding virtual channel as a session and mayacquire an SDP message with respect to the corresponding session. Morespecifically, according to the embodiment of the present invention, whenan SDP exists for each virtual channel, the position information of thecorresponding SDP message is received through the SDP referencedescriptor.

The SMT according to another embodiment of the present invention mayinclude a session description (SD) descriptor. And, in this case, thedigital broadcast receiving system may recognize (or acknowledge) thecorresponding virtual channel as a session and may acquire IP accessinformation and description information on the corresponding session.More specifically, according to the other embodiment of the presentinvention, the IP access information and description informationcorresponding to each stream component for each respective virtualchannel may be received through the SD descriptor. The SD descriptor mayprovide access information for each respective IP media component beingtransmitted though the corresponding session and access informationbased upon the corresponding media characteristic. Furthermore, the SDdescriptor may also provide Codec information for each component.

FIG. 25 illustrates an exemplary MH system architecture according to thepresent invention. Referring to FIG. 25, the system architectureprovides IP-based virtual channel service and rich media (RM) services.More specifically, the virtual channel services and RM serviceIP-packetized in the IP layer are first encapsulated into an MH TPwithin an RS frame. Thereafter, the encapsulated services are delivered(or transmitted) through a physical layer. At this point, in order toprovide and ensure fast channel setting on the IP-based virtual channelservice, a 2-step signaling method using FIC and SMT will be used. And,an IP-based signaling method is used for the IP-based services.

FIG. 26 illustrates a 2-step signaling method using the FIC and SMTaccording to the present invention. More specifically, the FIC providesthe receiving system with information on the IP-based virtual channelservice, more particularly, in which MH ensemble the correspondingIP-based virtual channel service exists. After receiving thecorresponding FIC information, the receiving system decodes the RS framecorresponding to the desired (or requested) MH ensemble. Subsequently,the receiving system acquires access information of the IP-based virtualchannel service within the corresponding MH ensemble through an SMTincluded in the decoded RS frame. Herein, the FIC includes informationlinking the MH ensemble to the virtual channel service. Furthermore,each row of the RS frame configures an MH TP, as shown in FIG. 3. EachMH TP is configured of any one of IP datagrams, signaling data, such asor SMT, and a combination of IP datagrams and signaling dataencapsulated therein. If the SMT exists in a well-known position (orpre-arranged position) within the RS frame, the receiving system may beable to process the SMT first when receiving the RS frame.

FIG. 27 illustrates an exemplary bit stream syntax structure of aservice map table (SMT) according to another embodiment of the presentinvention. The SMT shown in FIG. 27 is configured in an MPEG-2 privatesection format. However, this will not limit the scope of the presentinvention. The SMT includes description information for each virtualchannel within a single MH ensemble. And, other additional informationmay be included in the Descriptor field. The SMT includes at least onefield and is transmitted from the transmitting system (or transmitter)to the receiving system (or receiver). The difference between the SMTshown in FIG. 17 and the SMT shown in FIG. 27 is the presence of IPaccess information. More specifically, the SMT of FIG. 17 provides IPaccess information of virtual channels and/or IP access information ofIP stream components in a field format. Alternatively, when IP accessinformation of virtual channel or IP stream components are required, theSMT of FIG. 27 may provide the requested information through descriptorswithin a virtual channel loop.

Also, as described in FIG. 3, the SMT section may be included in an RSframe of the MH TP, which is then transmitted. In this case, each of theRS frame decoders 170 and 180 (shown in FIG. 1) decodes the inputted RSframe, and the decoded RS frame is outputted to each respective RS framehandler 211 and 212. Also, each RS frame handler 211 and 212distinguishes the inputted RS frame in row units, thereby configuring anMH TP. Then, each RS frame handler 211 and 212 outputs the configured MHTP to the MH TP handler 213.

When the system determines, based upon the header of each received MHTP, that the corresponding MH TP includes an SMT section, the MH TPhandler 213 parses the included SMT section. Then, the MH TP handler 213outputs the SI data included in the parsed SMT section to the physicaladaptation control signal handler 216. However, in this case, the SMT isnot encapsulated into IP datagrams.

Meanwhile, when the SMT is encapsulated into IP datagrams, and when thesystem determines, based upon the header of each received MH TP, thatthe corresponding MH TP includes an SMT section, the MH TP handler 213outputs the corresponding SMT section to the IP network stack 220.Accordingly, the IP network stack 220 performs IP and UDP processes onthe SMT section and outputs the processed SMT section to the SI handler240. The SI handler 240 parses the inputted SMT section and controls thesystem so that the parsed SI data are stored in the storage unit 290.

Examples of the fields that can be transmitted through the service maptable (SMT) will now be described.

A table_id field corresponds to an 8-bit unsigned integer number, whichindicates the type of table section being defined in the SMT.

An ensemble_id field corresponds to an 8-bit unsigned integer field, thevalue of which ranges from ‘0x00’ to ‘0x3F’. Herein, the value of theensemble_id field corresponds to an ID value associated with thecorresponding MH ensemble. It is preferable that the value of theensemble_id field is derived from the parade_id carried from thebaseband processor of MH physical layer subsystem. When thecorresponding MH ensemble is carried over (or transmitted through) theprimary RS frame, the most significant bit (MSB) is set to ‘0’, and theremaining (or least significant) 7 bits are used as identificationvalues (i.e., parade_id) of the corresponding MH ensemble. On the otherhand, when the corresponding MH ensemble is carried over (or transmittedthrough) the secondary RS frame, the most significant bit (MSB) is setto ‘1’, and the remaining (or least significant) 7 bits are used asidentification values (i.e., parade_id) of the corresponding MHensemble.

A num_channels field corresponds to an 8-bit field, which specifies thenumber of virtual channels in the corresponding SMT section.

Additionally, the SMT uses a ‘for’ loop statement so as to provideinformation on a plurality of virtual channels.

A transport_stream_ID field corresponds to a 16-bit field indicating anidentification value for distinguishing the corresponding SMT from otherSMTs that may be broadcasted via different physical channels.

A major_channel_num field corresponds to an 8-bit unsigned integerfield, which represents the major channel number associated with thecorresponding virtual channel. Herein, the major_channel_num field isassigned with a value ranging from ‘0x00’ to ‘0xFF’.

A minor_channel_num field corresponds to an 8-bit unsigned integerfield, which represents the minor channel number associated with thecorresponding virtual channel. Herein, the minor_channel_num field isassigned with a value ranging from ‘0x00’ to ‘0xFF’.

A source_id field corresponds to a 16-bit unsigned integer number, whichidentifies the programming source associated with the virtual channel.Accordingly, a source corresponds to any one specific source of video,text, data, and audio programs. The source_id field is not assigned withthe value ‘0’ (i.e., the source_id value zero (‘0’) is reserved). Thesource_id field is assigned with a value ranging from ‘0x0001’ to‘0x0FFF’. Herein, the source_id field value is a unique value, at theregional level, within the physical channel carrying the SMT.

A short_channel_name field indicates a short textual name of the virtualchannel.

Furthermore, the ‘for’ loop statement may further include a descriptors() field. The descriptors( ) field included in the ‘for’ loop statementcorresponds to a descriptor individually applied to each virtualchannel. The SDP reference descriptor or SD descriptor according to thepresent invention may be received by being included in any one of theSMT shown in FIG. 17 and the SMT shown in FIG. 27.

FIG. 28 illustrates an exemplary bit stream syntax structure of anSDP_Reference_Descriptor( ) according to the present invention.

Referring to FIG. 28, a descriptor_tag field is assigned with 8 bits.Herein, the descriptor_tag field indicates that the correspondingdescriptor is an SDP_Reference_Descriptor( ).

A descriptor_length field is an 8-bit field, which indicates the length(in bytes) of the portion immediately following the descriptor_lengthfield up to the end of the SDP_Reference_Descriptor( ).

An SDP_Reference_type field corresponds to an indicator indicatingwhether or not the corresponding SDP message is being transmitted in asession announcement protocol (SAP) stream format, or whether or not thecorresponding SDP message is being transmitted in an SDP file format viaa file delivery over unidirectional transport (FLUTE) session. Morespecifically, the SDP message may be received in a stream format and mayalso be received in a file format. When the SDP message is beingreceived in a stream format, the session announcement protocol (SAP) maybe used as the transmission protocol. On the other hand, when the SDPmessage is being received in a file format, the file delivery overunidirectional transport (FLUTE) protocol may be used as thetransmission protocol.

For example, when the SDP_Reference_type field value indicates the SAPstream, the SDP_Reference_Descriptor( ) may include an Address_typefield, an Address_count field, a Target_IP_address field, aTarget_Port_Num field, a Port_Count field, and a SDP_Session_ID field.

The Address_type field represents an indicator indicating whether thecorresponding IP address corresponds to an IPv4 address or an IPv6address.

The Address_count field indicates the number of IP streams that aretransmitted through the corresponding session. The address of each IPstream is assigned with a value increased by ‘1’ starting from the lastbit of the Target_IP_address field.

The Target_IP_address field either indicates an IP address of thecorresponding IP stream or indicates a representative IP address of thecorresponding session.

The Target_Port_Num field either indicates a UDP port number of thecorresponding IP stream or indicates a representative UDP port number ofthe corresponding session.

The Port_Count field indicates the number of port numbers that aretransmitted through the corresponding session. The UDP port number ofeach IP stream is assigned with a value increased by ‘1’ starting fromthe last bit of the Target_Port_Num field.

Finally, the SDP_Session_ID field represents an identifier assigned tothe SDP message respective of the corresponding virtual channel.

Meanwhile, when the SDP_Reference_type field value indicates the FLUTEfile delivery, the SDP_Reference_Descriptor( ) may include a TSI_lengthfield, an Address_type field, an Address_count field, aTransport_Session_ID field, a Target_IP_address field, a Target_Port_Numfield, a Port_Count field, and an SDP_Session_ID field.

The TSI_length field indicates to which of three options the length ofthe Transport_Session_ID field corresponds.

The Address_type field represents an indicator indicating whether thecorresponding IP address corresponds to an IPv4 address or an IPv6address.

The Address_count field indicates the number of IP streams that aretransmitted through the corresponding session. The address of each IPstream is assigned with a value increased by ‘1’ starting from the lastbit of the Target_IP_address field.

The Transport_Session_ID field represents an identifier for an IPaddress being transmitted (or delivered) to the respective session. Anyone of a 16-bit length, a 32-bit length, and a 64-bit length may beoptionally assigned as the length of the Transport_Session_ID field.

The Target_IP_address field either indicates an IP address of thecorresponding IP stream or indicates a representative IP address of thecorresponding session.

The Target_Port_Num field either indicates a UDP port number of thecorresponding IP stream or indicates a representative UDP port number ofthe corresponding session.

The Port_Count field indicates the number of port numbers that aretransmitted through the corresponding session. The UDP port number ofeach IP stream is assigned with a value increased by ‘1’ starting fromthe last bit of the Target_Port_Num field.

Finally, the SDP_Session_ID field represents an identifier assigned tothe SDP message respective of the corresponding virtual channel. Morespecifically, when an SDP message exists for each virtual channel, thereceiving system may be informed of the location information of acorresponding SDP message through the SDP reference descriptor, therebyenabling the receiving system to acquire the SDP message.

FIG. 29 illustrates an exemplary bit stream syntax structure of aSession_Description_Descriptor( ) according to the present invention.

Referring to FIG. 29, a descriptor_tag field is assigned with 8 bits.Herein, the descriptor_tag field indicates that the correspondingdescriptor is a Session_Description_Descriptor( ) (i.e., SD descriptor).

A descriptor_length field is an 8-bit field, which indicates the length(in bytes) of the portion immediately following the descriptor_lengthfield up to the end of the Session_Description_Descriptor( ).

A Session_version field indicates the version of the correspondingsession.

An Address_type field represents an indicator indicating whether thecorresponding IP address corresponds to an IPv4 address or an IPv6address.

A Target_IP_address field either indicates an IP address of thecorresponding IP stream or indicates a representative IP address of thecorresponding session.

An Address_count field indicates the number of IP streams that aretransmitted through the corresponding session. The address of each IPstream is assigned with a value increased by ‘1’ starting from the lastbit of the Target_IP_address field.

A Num_components field indicates the number of components included inthe corresponding virtual channel.

The SD descriptor (i.e., Session_Description_Descriptor( )) uses a ‘for’loop statement so as to provide information on a plurality ofcomponents.

Herein, the ‘for’ loop statement may includes a Media_type field, aNum_Ports field, a Target_Port_Num field, an RTP_payload_type field, aCodec_type field, and an MPEG4_ES_ID field.

The Media_type field indicates the media type of the correspondingcomponent. For example, the Media_type field indicates whether thecomponent corresponds to audio-type media, video-type media, ordata-type media.

The Num_ports field indicates the number of ports transmitting (ordelivering) the corresponding component.

The Target_Port_Num field indicates the UDP port number of thecorresponding component.

The RTP_payload_type field represents the coding format of thecorresponding. In case the corresponding component has not beenencapsulated to RTP, the RTP_payload_type field shall be disregarded.

The Codec_type field indicates to which Codec type the correspondingcomponent has been encoded. For example, if the component corresponds tovideo-type media, H.264 or SVC may be used as the Codec type of thevideo component.

The MPEG4_ES_ID field represents an identifier that can identify anMPEG4 element stream (ES) of the corresponding component.

When the Media_type field value indicates video-type media, and when thecodec_type field value indicates the H.264, theSession_Description_Descriptor( ) may further include anAVC_Video_Description_Bytes( ) field.

Also, when the Media_type field value indicates video-type media, andwhen the codec_type field value indicates the SVC, theSession_Description_Descriptor( ) may further include anAVC_Video_Description_Bytes( ) field, a Hierarchy_Description_Bytes( )field, and an SVC_extension_Description_Bytes( ) field.

Moreover, when the Media_type field value indicates audio-type media,the Session_Description_Descriptor( ) may further include anMPEG4_Audio_Description_Bytes( ) field.

The above-described AVC_Video_Description_Bytes( ) field, theHierarchy_Description_Bytes( ) field, theSVC_extension_Description_Bytes( ) field, and theMPEG4_Audio_Description_Bytes( ) field respectively include parametersthat are used when decoding the corresponding component.

FIG. 30 illustrates an exemplary bit stream syntax structure of anAVC_Video_Description_Bytes( ) according to the present invention. TheAVC_Video_Description_Bytes( ) may include a profile_idc field, aconstraint_set0_flag field, a constraint_set1_flag field, aconstraint_set2_flag field, a constraint_set3_flag field, anAVC_compatible_flags field, a level_idc field, an AVC_still_presentfield, and an AVC_(—)24_hour_picture_flag field.

More specifically, the profile_idc field indicates a profile of thecorresponding video. The constraint_set0_flag to constraint_set3_flagfields respectively indicate a satisfaction status of the constraintrespective of the corresponding profile.

The level_idc field indicates the level of the corresponding video. Forexample, the level_idc field defined in ISO/IEC 14496-10 may be usedwithout modification as the level_idc field included inAVC_Video_Description_Bytes( ) according to the embodiment of thepresent invention.

FIG. 31 illustrates an exemplary bit stream syntax structure of aHierarchy_Description_Bytes( ) according to the present invention. TheHierarchy_Description_Bytes( ) may include a temporal_scalability_flagfield, a spatial_scalability_flag field, a quality_scalability_flagfield, a hierarchy_type field, a hierarchy_layer_index field, ahierarchy_embedded_layer_index field, and a hierarchy_channel field.More specifically, the temporal_scalability_flag field indicates atemporal scalability status of the corresponding video.

The spatial_scalability_flag field indicates a spatial scalabilitystatus of the corresponding video. And, the quality_scalability_flagfield indicates a qualitative scalability status of the correspondingvideo.

FIG. 32 illustrates an exemplary bit stream syntax structure of anSVC_extension_Description_Bytes( ) according to the present invention.Herein, the SVC_extension_Description_Bytes( ) may include a profile_idcfield, a level_idc field, a width field, a height field, a frame_ratefield, an average_bitrate field, a maximum_bitrate field, adependency_id field, a quality_id_start field, a quality_id_end field, atemporal_id_start field, and a temporal_id_end field.

More specifically, the profile_idc field indicates a profile of thecorresponding video.

The level_idc field indicates the level of the corresponding video.

The width field indicates the horizontal size (i.e., width) of thescreen on which the corresponding video is to be displayed.

The height field indicates the vertical size (i.e., height) of thescreen on which the corresponding video is to be displayed.

The frame_rate field indicates a frame rate of the corresponding video.

The average_bitrate field indicates the average bit transmission rate ofthe corresponding video.

And, the maximum_bitrate field indicates the maximum bit transmissionrate of the corresponding video.

FIG. 33 illustrates an exemplary bit stream syntax structure of anMPEG4_Audio_Description_Bytes( ) according to the present invention. TheMPEG4_Audio_Description_Bytes( ) may include anMPEG4_audio_profile_and_level field.

Herein, the MPEG4_audio_profile_and_level field indicates a profile anda level value of the corresponding audio.

By receiving the SD descriptor included in the SMT, and by using thereceived SD descriptor, the receiving system according to the presentinvention may acquire description information including IP accessinformation and Codec information on each component for each respectivevirtual channel. If the received SD descriptor is included in the SMTshown in FIG. 17, then the IP access information for a correspondingcomponent may be omitted from the SD descriptor.

As described above, the description information on each component (i.e.,Codec information) may be received by being included in the SMT shown inFIG. 17 as the component level descriptor. Alternatively, thedescription information on each component (i.e., Codec information) maybe described in the SD descriptor in a text format, and the SDdescriptor may be received by being included either in the SMT shown inFIG. 17 or in the SMT shown in FIG. 27 as the virtual channel leveldescriptor.

If the description information on each component (i.e., Codecinformation) is received by being included in the SMT of FIG. 17 as thecomponent level descriptor, the description information would be moreeffective in describing the Codec information of the component, which isencoded in a Codec pre-decided by a specific standard. On the otherhand, if the description information on each component (i.e., Codecinformation) is described in the SD descriptor in a text format, and ifthe SD descriptor is received by being included either in the SMT ofFIG. 17 or in the SMT of FIG. 27 as the virtual channel leveldescriptor, the description information would be more effective indescribing the Codec information of the component, which is encoded inan undecided Codec.

Since the value of each field is pre-decided, the former case isadvantageous in that the descriptor size is small and the processing issimplified. However, the disadvantage of the former case is that onlythe information of the pre-decided Codec can be described.Alternatively, since the Codec information is provided in a text formatvia the SD descriptor, the latter case is disadvantageous in that thedescriptor size for the Codec information may become larger. However,the latter case has an advantage in expandability, since the informationmay be described even though the corresponding component is coded in anundecided Codec.

An example of accessing the SDP message by referring to the SDPdescriptor or the SD descriptor, so as to acquire SDP messageinformation will now be described in detail. For example, it is assumedthat the SMT is encapsulated into IP datagrams, so as to be received.Accordingly, when the system determines, based upon the header of eachreceived MH TP, that the corresponding MH TP includes an SMT section,the MH TP handler 213 outputs the corresponding SMT section to the IPnetwork stack 220. Thereafter, the IP network stack 220 performs IP andUDP processes on the SMT section and outputs the processed SMT sectionto the SI handler 240. The SI handler 240 parses the inputted SMTsection and controls the system so that the parsed SI data are stored inthe storage unit 290.

At this point, when an SDP reference descriptor (shown in FIG. 28) isincluded in the SMT section, the SI handler 240 acquires positioninformation of the corresponding SDP message from the SDP referencedescriptor. Among the position information, the SI handler 240 may usethe SDP reference type information to determine whether thecorresponding SDP message is being received in an SAP stream format, orwhether the corresponding SDP message is being received in an SDP fileformat through a FLUTE session. If it is determined that the SDP messageis being received in an SAP stream format, the SI handler 240 parses thevalue of each of the Address_type field, the Address_count field, theTarget_IP_address field, the Target_Port_Num field, the Port_Countfield, and the SDP_Session_ID field, which are all included in thedescriptor. Then, the SI handler 240 refers to the parsed values toaccess the corresponding SAP stream, which is then outputted to the MIMEhandler 260. Thereafter, the MIME handler 260 gathers (or collects) SDPmessage information from the inputted SAP stream, thereby storing thegathered (or collected) SDP message information in the storage unit 290through the SI handler 240.

Alternatively, if it is determined that the SDP message is beingreceived in an SDP file format through a FLUTE session, the SI handler240 parses the value of each of the TSI_length field, the Address_typefield, the Address_count field, the Transport_Session_ID field, theTarget_IP_address field, the target_Port_Num field, the Port_Countfield, and the SDP_Session_ID field, which are all included in thedescriptor. Then, the SI handler 240 refers to the parsed values toaccess the corresponding FLUTE session, which is then outputted to theFLUTE handler 250. The FLUTE handler 250 extracts the SDP file from theinputted FLUTE session, which is then outputted to the MIME handler 260.The MIME handler 260 gathers SDP message information from the inputtedSDP file, thereby storing the gathered SDP message information in thestorage unit 290 through the SI handler 240.

Meanwhile, when an SD descriptor (shown in FIG. 29) is included in theSMT section, the SI handler 240 acquires IP access information anddescription information on each component within the correspondingvirtual channel from the SD descriptor. For example, the SI handler 240extracts media-type information and Codec-type information from the SDdescriptor. Then, the SI handler 240 acquires Codec information of thecorresponding component based upon the extracted media-type informationand Codec-type information. The acquired Codec information is thenstored in the storage unit 290. When required, however, the acquiredCodec information is outputted to the A/V decoder 310.

If the media type corresponds to a video component, and if the Codectype corresponds to H.264, the SI handler 240 parses theAVC_Video_Description_Bytes( ), thereby acquiring the Codec informationof the corresponding video component.

Meanwhile, if the media type corresponds to a video component, and ifthe Codec type corresponds to SVC, the SI handler 240 parses theAVC_Video_Description_Bytes( ), the Hierarchy_Description_Bytes( ), andthe SVC_extension_Description_Bytes( ), thereby acquiring the Codecinformation of the corresponding video component. Furthermore, if themedia type corresponds to an audio component, the SI handler 240 parsesthe MPEG4_Audio_Description_Bytes( ), thereby extracting the Codecinformation of the corresponding audio component.

FIG. 34 to FIG. 36 illustrate flow charts showing a method for accessinga mobile service according to an embodiment of the present invention.FIG. 34 illustrates an example of a method for accessing a mobileservice using one of the SDP reference descriptor and SD descriptor inthe receiving system according to the present invention. Morespecifically, a physical channel is tuned (S701). And, FIC segments aregathered in sub-frame units through an MH sub-frame of the tuned MHsignal, so as to be demodulated (S702). According to the embodiment ofthe present invention, an FIC segment is inserted in a data group, so asto be transmitted. More specifically, the FIC segment corresponding toeach data group described service information on the MH ensemble towhich the corresponding data group belongs. When the FIC segments aregathered (or grouped) in sub-frame units and, then, deinterleaved, allservice information on the physical channel through which thecorresponding FIC segment is transmitted may be acquired. Therefore,after the tuning process, the receiving system may acquire channelinformation on the corresponding physical channel during a sub-frameperiod.

In Step 702, when the FIC data are processed, reference may be made tothe processed FIC data, so as to locate (or detect) the MH ensembletransmitting the requested mobile service (S703). Then, data groupsincluding the MH ensemble are gathered from the MH frame, so as toconfigure an RS frame corresponding to the MH ensemble, thereby decodingthe configured RS frame (S704). Thereafter, an MH TP, which transmits anSMT from the decoded RS frame, is located (or found) (S705). Each fieldof the SMT found in Step 705 is parsed, so as to gather descriptiveinformation on each virtual channel (S706).

If the SMT corresponds to the SMT of FIG. 17, the descriptiveinformation may correspond to a major channel number, a minor channelnumber, a virtual channel short name, service ID, service type, activitystatus information on the corresponding virtual channel, IP addressinformation, UDP port information, and so on. Alternatively, if the SMTcorresponds to the SMT of FIG. 27, the descriptive information maycorrespond to a transport stream ID, a major channel number, a minorchannel number, a source ID, a channel short name, and so on.

Once the descriptive information is gathered, the descriptors within thevirtual channel loop of the SMT are gathered and processed (S707). Atthis point, the system determines whether an SDP reference descriptor(as shown in FIG. 28) or an SD descriptor (as shown in FIG. 29) isincluded in the descriptors within the virtual channel loop of the SMT(S708). If the system determines, in Step 708, that the SDP referencedescriptor is included in the virtual channel loop of the SMT, theprocess step moves on to the steps shown in FIG. 35, thereby acquiringposition information of the corresponding SDP message from the SDPreference descriptor (S709).

Alternatively, if the system determines, in Step 708, that the SDdescriptor is included in the virtual channel loop of the SMT, theprocess step moves on to the steps shown in FIG. 36, thereby acquiringIP access information and description information for each component ofthe corresponding virtual channel from the SD descriptor (S710). Afterprocessing Steps 709 and 710, the system verifies for any remainingunprocessed virtual channels (S711). If the system detects unprocessedvirtual channels, Step 706 is repeated so as to gather more informationon the corresponding virtual channel. Conversely, if the system does notdetect any unprocessed virtual channels, the system prepares to providethe mobile service (S712).

When it is determined in FIG. 34 that an SDP reference descriptor isincluded in the parsed SMT, FIG. 35 illustrates a flow chart of a methodfor acquiring position information of the corresponding SDP message.More specifically, the receiving system extracts SDP reference typeinformation from the SDP reference descriptor (S801). Then, it isdetermined whether the extracted SDP reference type information is beingreceived in an SAP stream format, or whether the extracted SDP referencetype information is being received in an SDP file format through a FLUTEsession (S802).

If the system determines, in Step 802, that the extracted SDP referencetype information is being received in an SAP stream format, the value ofeach of the Address_type field, the Address_count field, theTarget_IP_address field, the Target_Port_Num field, the Port_Countfield, and the SDP_Session_ID field, which are all included in thedescriptor, is parsed. And, the system refers to the parsed field valuesto access the corresponding SAP stream (S803). Then, the system gathersSDP message information from the accessed SAP stream, so as to providethe information to the respective block, thereby moving on to thesubsequent process steps shown in FIG. 34 (S804).

On the other hand, if the system determines, in Step 802, that theextracted SDP reference type information is being received in an SDPfile format through a FLUTE session, the value of each of the TSI_lengthfield, the Address_type field, the Address_count field, theTransport_Session_ID field, the Target_IP_address field, thetarget_Port_Num field, the Port_Count field, and the SDP_Session_IDfield, which are all included in the descriptor, is parsed. And, thesystem refers to the parsed field values to access the correspondingFLUTE session (S805). Then, the system gathers SDP message informationfrom the accessed FLUTE session, so as to provide the information to therespective block, thereby moving on to the subsequent process stepsshown in FIG. 34 (S806).

When it is determined in FIG. 34 that an SD descriptor is included inthe parsed SMT, FIG. 35 illustrates a flow chart of a method foracquiring IP access information and description information on eachcomponent within the corresponding virtual channel. More specifically,IP address information is extracted from the SD descriptor (S901).Herein, the IP address information may be acquired by parsing theSession_version field, the Address_type field, the Target_IP_addressfield, and the Address_count field. Then, with respect to each componentwithin the virtual channel, media type information (Media_type) isextracted from the SD descriptor (S902), and UDP/RTP information isextracted from the SD descriptor (S903). Herein, the UDP/RTP informationmay be acquired by parsing the Num_Ports field, the Target_Port_Numfield, and the RTP_payload_type field.

Subsequently, the receiving system determines whether the media typeextracted in Step 902 corresponds to a video component or an audiocomponent (S904). When it is verified in Step 904 that the media typecorresponds to a video component, Codec type (codec_type) information isextracted (S905). Thereafter, Codec information of the correspondingvideo component is acquired based upon the extracted Codec type (S906).For example, when the Codec type indicates H.264, the receiving systemparses the AVC_Video_Description_Bytes( ). Meanwhile, when the Codectype indicates SVC, the receiving system parses theAVC_Video_Description_Bytes( ), the Hierarchy_Description_Bytes( ), andthe SVC_extension_Description_Bytes( ), thereby acquiring Codecinformation of the corresponding video component (S906). Thereafter, theacquired video Codec information is outputted to the A/V decoder 310.

Alternatively, when it is verified in Step 904 that the media typecorresponds to an audio component, Codec type (codec_type) informationis extracted (S907). Then, the receiving system parses theMPEG4_Audio_Description_Bytes( ), thereby extracting the Codecinformation of the corresponding audio component (S908). Thereafter, theacquired audio Codec information is also outputted to the A/V decoder310. Based upon the Codec information of the inputted video and/or audiocomponent(s), the A/V decoder 310 decodes audio and/or video stream(s)outputted from the stream handler 230, thereby outputted the decodedstream(s) to the display module 320.

As described above, the digital broadcasting system and the dataprocessing method according to the present invention have the followingadvantages. By using the SMT, the present invention may perform channelsetting more quickly and efficiently. Also, either by including an SDPreference descriptor describing position information on an SDP messagein the SMT, or by including an SD descriptor describing IP accessinformation and description information on each component of therespective virtual channel, so as to be transmitted, the presentinvention may expand information associated with channel settings.

Also, the present invention reduces the absolute amount of acquisitiondata for channel setting and IP service access, thereby minimizingbandwidth consumption. For example, when the SDP reference descriptor isincluded in the SMT and received, the corresponding virtual channel isrecognized as a session, and the SDP message of the correspondingsession may be received. Also, when the SD descriptor is included in theSMT and received, the corresponding virtual channel is recognized as asession, thereby enabling access information based upon the accessinformation and media characteristics of each IP media component, whichis being transmitted through the corresponding session.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the inventions. Thus, itis intended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A method of transmitting broadcast data in a digital broadcasttransmitting system, the method comprising: Reed Solomon-CyclicRedundancy Check (RS-CRC) encoding, by a Reed-Solomon (RS) frameencoder, mobile data to build at least one of a primary RS framebelonging to a primary ensemble and a secondary RS frame belonging to asecondary ensemble; mapping the RS-CRC encoded mobile data into datagroups and adding known data sequences, a portion of fast informationchannel (FIC) data, and transmission parameter channel (TPC) data toeach of the data groups, wherein the FIC data includes information forrapid mobile service acquisition, and wherein the TPC data includesversion information for indicating an update of the FIC data and aparade identifier to identify a parade which carries at least one of theprimary ensemble and the secondary ensemble; multiplexing data in thedata groups and main data; and transmitting a transmission frameincluding the multiplexed data, wherein the FIC data are divided into aplurality of FIC segment payloads, and each FIC segment including an FICsegment header and one of the plurality of FIC segment payloads istransmitted in each of the data groups, wherein the primary ensembleincludes at least one mobile service and a first service map table andthe secondary ensemble includes at least one mobile service and a secondservice map table, wherein the first service map table comprises a firstensemble identifier to identify the primary ensemble and the secondservice map table comprises a second ensemble identifier to identify thesecondary ensemble, and wherein the first and second ensembleidentifiers include the parade identifier, respectively.
 2. The methodof claim 1, wherein a most significant bit of the first ensembleidentifier is set to
 0. 3. The method of claim 1, wherein a mostsignificant bit of the second ensemble identifier is set to
 1. 4. Themethod of claim 1, wherein a least significant 7 bits of the firstensemble identifier correspond to the parade identifier.
 5. The methodof claim 1, wherein a least significant 7 bits of the second ensembleidentifier correspond to the parade identifier.
 6. A digital broadcasttransmitting system comprising: a Reed-Solomon (RS) frame encoder forReed Solomon-Cyclic Redundancy Check (RS-CRC) encoding mobile data tobuild at least one of a primary RS frame belonging to a primary ensembleand a secondary RS frame belonging to a secondary ensemble; a groupformatting means for mapping the RS-CRC encoded mobile data into datagroups and adding known data sequences, a portion of fast informationchannel (FIC) data, and transmission parameter channel (TPC) data toeach of the data groups, wherein the FIC data includes information forrapid mobile service acquisition, and wherein the TPC data includesversion information for indicating an update of the FIC data and aparade identifier to identify a parade which carries at least one of theprimary ensemble and the secondary ensemble; a multiplexing means formultiplexing data in the data groups and main data; and a transmittingmeans for transmitting a transmission frame including the multiplexeddata, wherein the FIC data are divided to a plurality of FIC segmentpayloads, and each FIC segment including an FIC segment header and oneof the plurality of FIC segment payloads is transmitted in each of thedata groups, wherein the primary ensemble includes at least one mobileservice and a first service map table and the secondary ensembleincludes at least one mobile service and a second service map table,wherein the first service map table comprises a first ensembleidentifier to identify the primary ensemble and the second service maptable comprises a second ensemble identifier to identify the secondaryensemble, and wherein the first and second ensemble identifiers includethe parade identifier, respectively.
 7. The digital broadcasttransmitting system of claim 6, wherein a most significant bit of thefirst ensemble identifier is set to
 0. 8. The digital broadcasttransmitting system of claim 6, wherein a most significant bit of thesecond ensemble identifier is set to
 1. 9. The digital broadcasttransmitting system of claim 6, wherein a least significant 7 bits ofthe first ensemble identifier correspond to the parade identifier. 10.The digital broadcast transmitting system of claim 6, wherein a leastsignificant 7 bits of the second ensemble identifier correspond to theparade identifier.